Posts with «android» label

Review – pcDuino v2

Introduction

Updated 29/01/2014 All pcDuino v2 tutorials

Update! The pcDuino version 3 is now available

In the last twelve months or so several somewhat inexpensive single-board computers have burst onto the market, and of those was the pcDuino. This has now evolved into the pcDuino v2, the topic of our review. The pcDuino v2 is billed as the “mini PC + Arduino”, a combination with much promise. Out of the box it runs a version of Ubuntu 12.04 on Linaro 12.07, or can also run Android Ice Cream Sandwich if so desired.

The pcDuino v2 is a single-board computer like many others, however with some interesting additions – the most interesting being the Arduino-shield hardware connections and pcDuino v2 Arduino development environment. We’ll first run through the pcDuino v2 as a Linux computer, and then delve into the Arduino-compatibility. But first, our test board… which arrived safely in a neat box:

… which contains the pcDuino v2 itself:

At first glance you can see the various points of interest, such as the Allwinner A10, which is a 1GHz ARM Cortex A8 CPU:

… the Realtek WiFi add-on board (which is fitted to the pcDuino v2):

… and also a USB socket (for keyboard, mouse, USB hub and so on), a microUSB for USB OTG use, a full-sized HDMI socket for full HD video, RJ45 Ethernet socket, a microSD socket for expansion, and the Hynix flash memory ICs. From the pcDuino v2 website, the specifications are:

Hardware:

CPU – 1GHz ARM Cortex A8
GPU – OpenGL ES2.0, OpenVG 1.1 Mali 400 core
DRAM – 1GB
Onboard Storage – 2GB Flash, microSD card (TF) slot for up to 32GB
Video Output – HDMI
OS – Linux3.0 + Ubuntu 12.04/Android ICS 4.0
Extension Interface Arduino Headers
Network interface – 10/100Mbps RJ45 and on-board WiFi module
USB Host port 1
Requires – Power 5V, 2000mA
Overall Size 125mm X 52mm

Software

OS – Ubuntu 12.04 (pre-loaded) or Android ICS 4.0
APIs – all the Arduino shield pins are accessible with the provided API.
It consists of API to access the following interfaces: UART, ADC, PWM, GPIO, I2C, SPI
Programming language support – C, C++ with GNU tool chain, Java with standard Android SDK, Python.

However at the time of writing all models with the date stamp of 17/09/2013 (and newer) have 4G of onboard flash storage – a great little bonus. With the addition of an inexpensive microSD card you can add up to an additional 32 G of storage.

Getting Started

This is the crunch-point for many products – how does one get started? With the pcDuino – very easily. Apart from the computer itself, you’ll need a monitor with HDMI inputs and speakers, a USB keyboard and mouse (with a USB hub – or one of those keyboard/trackpad combinations) and a power supply. The pcDuino v2 requires up to 2A at 5V – a higher-rated plugpack than usual. Don’t be tempted to use a normal USB socket – the pcDuino v2 will not work properly on the available current.

So after plugging all that in with the power the last to connect – the pcDuino v2 fires up in around five seconds, quickly running through the Ubuntu startup process and ended with the configuration screen in around five seconds:

After setting the time zone, language, screen resolution (full HD) and so on it was another ten seconds to the desktop:

At this point we found by accident that the A10 CPU runs hot – in some warmer permanent installations it could use a heatsink. But I digress. We now have a “normal” computer experience – the WiFi found the home network without any issue and the Chromium web browser runs well considering the speed and the RAM (1G) of the pcDuino v2:

The next step is to format the extra onboard storage, which can be done with the usual tool:

We just formatted it to ext4 and moved on. The included software is nothing unexpected, there’s the Chromium web browser, office-style applications, terminal, XBMC, remote-desktop viewer and of course you can hit up the Ubuntu package manager and install what you need.

It’s easy to get carried away and forget you’re not using a typical multi-GHz computer so bear that in mind when software runs a little slower than expected. However working with WordPress and Google Docs inside Chromium was acceptable, and a fair amount of this review was written using the pcDuino v2.

Excluding the Arduino development environment which we look at in the next section, pre-installed programming tools include Python (v2.7), C/C++ with GNU tool chain and Java with the standard Android SDK. At this point we haven’t tried the pcDuino with the Android operating system, however plan to do so in the near future and this will be the subject of a separate article.

At this point we’d say that the pcDuino v2 is a winner in the SBC (single-board computer) stakes, as you don’t need to worry about external WiFi, or deliberating about which version of an OS to use and then having to download it to an SD card and so on… the pcDuino v2 just works as a computer out of the box.

The pcDuino v2 as an Arduino

At this point we’d like to note that the pcDuino v2 is not an Arduino circuit wired up to a computer (such as the Arduino team did with the Yun). Instead, the pcDuino v2 is a computer that can emulate an Arduino – and has the GPIO pins and shield sockets onboard.

So when you run a sketch on the pcDuino v2’s version of the Arduino IDE – the sketch is compiled and then executed using the CPU, not an ATmega microcontroller. Speaking of which, the IDE is a modified version of 1.5.3 which appears identical to the usual IDE:

In fact when you compile and upload that blink.ino sketch everything runs as normal, and a small LED situated near D2／3 will blink as normal. However you do need to use more #include statements, for example #include <core.h> for all sketches. When uploading a sketch, a new window appears that will be blank, as shown below – this window needs to stay open otherwise the sketch won’t run

One of the benefits of using the pcDuino v2 is the extra space available for sketches – a quick compile shows that you can have a fair bit more than your typical ATmega328 – in our example we had 104,857,600 bytes available:

We don’t have a sketch that large, but at least you have some headroom to create them if necessary.

Arduino Hardware support

The shield header sockets are in the standard R3 configuration – and all GPIO is 3.3V and not 5V tolerant. However there is a conversion shield available if necessary. There are also some extra GPIO pins available – another eight, as shown in the following image:

At the time of writing there is support for GPIO use, SPI (up to 12 MHz, master-only), I2C (up to 200 kHz, at 7-bit and master-only), a UART (serial on D0/D1), PWM and ADC on A0~5.

However ADC is a little different, due to the internal reference voltages of the Allwinner CPU. Take note of the following as if you exceed the maximum voltages you could damage your board. Pins A0 and A1 are 6-bit ADCs, which return values from 0 ~ 63, which range from 0V to 2V. Pins A2~A5 are 12-bit ADCs, which return values from 0 ~ 4095, which range across the full 0V to 3.3V.

There isn’t access to the usual serial monitor in the Arduino IDE as such, instead you need to use an external, hardware-based solution such as connecting a USB-serial adaptor to pins D0/D1 and using another PC as the terminal. And when you press ‘reset’ on your Arduino shields – it resets the entire computer, just not the Arduino emulation – (learned that the hard way!).

However you can output text and data to the console window that appears after uploading a sketch – and doing so is pretty easy, just use prinf as you would in C or C++. For example, the following sketch:

#include <core.h>

// example code from http://www.cplusplus.com/reference/cstdio/printf/

void setup() {
  // put your setup code here, to run once:

}

void loop() 
{
   printf ("Characters: %c %c \n", 'a', 65);
   printf ("Decimals: %d %ld\n", 1977, 650000L);
   printf ("Preceding with blanks: %10d \n", 1977);
   printf ("Preceding with zeros: %010d \n", 1977);
   printf ("Some different radices: %d %x %o %#x %#o \n", 100, 100, 100, 100, 100);
   printf ("floats: %4.2f %+.0e %E \n", 3.1416, 3.1416, 3.1416);
   printf ("Width trick: %*d \n", 5, 10);
   printf ("%s \n", "A string");
  delay(1000);
}

produces the following output in the console window:

It would be recommended to read this guide about using the pcDuino v2 as an Arduino which highlights pretty well everything to get you started, including the notes on interrupts and PWM – and this page which explains the headers on the pcDuino v2. Finally, as the “Arduino” is emulated you cannot use the on-board networking capabilities of the pcDuino v2 such as Ethernet, instead you use a shield as you would with a normal Arduino.

At first glance it may seem that the pcDuino v2 is difficult, which it is not. One needs instead to consider their needs and then work with the available features. Just like many other new development boards and systems, the pcDuino v2 (and pcDuino platform) is still quite new – but growing – so more features and compatibility will appear over time.

How much faster is the pcDuino v2 against a normal Arduino board?

There should be a great difference between the Arduino’s microcontroller and the A10 CPU, even taking into account running the OS and emulation. To test this, we’ll use a sketch written by Steve Curd from the Arduino forum. It calculates Newton Approximation for pi using an infinite series. The pcDuino v2 version of the sketch is below:

//
// Pi_2
//
// Steve Curd
// December 2012
//
// This program approximates pi utilizing the Newton's approximation.  It quickly
// converges on the first 5-6 digits of precision, but converges verrrry slowly
// after that.  For example, it takes over a million iterations to get to 7-8
// significant digits.
//
// I wrote this to evaluate the performance difference between the 8-bit Arduino Mega,
// and the 32-bit Arduino Due.
// 

#include <core.h> // for pcDuino v2
#include "Serial.h"

#define ITERATIONS 100000L    // number of iterations
#define FLASH 1000            // blink LED every 1000 iterations

void setup() {
  pinMode(13, OUTPUT);        // set the LED up to blink every 1000 iterations
  Serial.begin(57600);
}

void loop() {

  unsigned long start, time;
  unsigned long niter=ITERATIONS;
  int LEDcounter = 0;
  boolean alternate = false;
  unsigned long i, count=0;
  float x = 1.0;
  float temp, pi=1.0;

  Serial.print("Beginning ");
  Serial.print(niter);
  Serial.println(" iterations...");
  Serial.println();

  start = millis();  
  for ( i = 2; i < niter; i++) {
    x *= -1.0;
    pi += x / (2.0f*(float)i-1.0f);
    if (LEDcounter++ > FLASH) {
      LEDcounter = 0;
      if (alternate) {
        digitalWrite(13, HIGH);
        alternate = false;
      } else {
        digitalWrite(13, LOW);
        alternate = true;
      }
      temp = 40000000.0 * pi;
    }
  }
  time = millis() - start;

  pi = pi * 4.0;

  Serial.print("# of trials = ");
  Serial.println(niter);
  Serial.print("Estimate of pi = ");
  Serial.println(pi, 10);

  Serial.print("Time: "); Serial.print(time); Serial.println(" ms");

  delay(10000);
}

As mentioned earlier, you can’t see the IDE serial monitor, so an external PC needs to be used. We connected a USB-serial adaptor running at 3.3V I/O to a PC:

Now back to the sketch. An Arduino Mega 2560 can do the calculation in 5765 ms, a Due 690 ms, and the fastest I saw the emulated Arduino in the pcDuino v2 do it was 9 ms:

Wow, that’s quick. However take note that the completion time was all over the place. When it was 9ms, the only application open was the pcDuino v2 Arduino IDE. The completion time increased when opening other applications such as Chromium, formatting a microSD card and so on.

Why is that? As the pcDuino v2 is emulating an Arduino, the CPU needs clock cycles to take care of that and all the other OS tasks – whereas a straight Arduino just runs the code generated by the IDE and compiler. Nevertheless the speed increase is welcome, and opens up all sorts of possibilities with regards to deeper calculations in sketches they may taken too long on existing hardware.

Support and Community

From what I can tell there is a growing base of users (including this one) and like everything else this will help the pcDuino platform develop and evolve over time. There is a Linksprite “Learning Centre” with a growing pcDuino v2 section, the website, wiki, and support forum which are useful sources of information and discussion.

Conclusion – so far

The pcDuino v2 is a great mix of single-board computer and Arduino-compatible power. There is a small learning curve, however the performance gains are more than worth it. Another USB socket wouldn’t go astray, and the documentation and support will increase over time. However we really liked the fact it’s totally plug-and-play with the onboard storage, OS and WiFi.

And finally a plug for my own store – tronixlabs.com – offering a growing range and Australia’s best value for supported hobbyist electronics from adafruit, DFRobot, Freetronics, Seeed Studio and much more.

Have fun and keep checking into tronixstuff.com. Why not follow things on twitter, Google+, subscribe for email updates or RSS using the links on the right-hand column, or join our forum – dedicated to the projects and related items on this website.

The post Review – pcDuino v2 appeared first on tronixstuff.

Tronixstuff 13 Jan 01:15

android arduino arm cortex a8 armwinner ics ide java pcduino python review tronixstuff tutorial ubuntu wifi

Bluetooth Android Processing 3

PART THREE

If you happened to land on this page and missed PART ONE, and PART TWO, I would advise you go back and read those sections first.

This is what you'll find in partone:

Downloading and setting up the Android SDK
Downloading the Processing IDE
Setting up and preparing the Android device
Running through a couple of Processing/Android sketches on an Andoid phone.

This is what you will find in part two:

Introducing Toasts (display messages)
Looking out for BluetoothDevices using BroadcastReceivers
Getting useful information from a discovered Bluetooth device
Connecting to a Bluetooth Device
An Arduino Bluetooth Sketch that can be used in this tutorial

InputStream and OutputStream

We will now borrow some code from the Android developers site to help us to establish communication between the Android phone and the Bluetooth shield on the Arduino. By this stage we have already scanned and discovered the bluetooth device and made a successful connection. We now need to create an InputStream and OutputStream to handle the flow of communication between the devices. Let us start with the Android/Processing Side.
The Android Developers site suggests to create a new Thread to handle the incoming and outgoing bytes, because this task uses "blocking" calls. Blocking calls means that the application will appear to be frozen until the call completes. We will create a new Thread to receive bytes through the BluetoothSocket's InputStream, and will send bytes to the Arduino through the BluetoothSocket's OutputStream.
This Thread will continue to listen/send bytes for as long as needed, and will eventually close when we tell it to. We will also need a Handler() to act on any bytes received via the InputStream. The Handler is necessary to transfer information from the IO Thread to the main application thread. This is done by using a Message class. Here is a summary of relevant code that we will subsequently add to the ConnectBluetooth sketch (which was described in Part Two of this tutorial):

import android.bluetooth.BluetoothSocket;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

// Message types used by the Handler
public static final int MESSAGE_WRITE = 1;
public static final int MESSAGE_READ = 2;

// The Handler that gets information back from the Socket
private final Handler mHandler = new Handler() {
 @Override
 public void handleMessage(Message msg) {
 switch (msg.what) {
 case MESSAGE_WRITE:
 //Do something when writing
 break;
 case MESSAGE_READ:
 //Get the bytes from the msg.obj
 byte[] readBuf = (byte[]) msg.obj;
 // construct a string from the valid bytes in the buffer
 String readMessage = new String(readBuf, 0, msg.arg1);
 break;
 }
 }
};



private class SendReceiveBytes implements Runnable {
 private BluetoothSocket btSocket;
 private InputStream btInputStream = null;
 private OutputStream btOutputStream = null;
 String TAG = "SendReceiveBytes";

 public SendReceiveBytes(BluetoothSocket socket) {
 btSocket = socket;
 try {
 btInputStream = btSocket.getInputStream();
 btOutputStream = btSocket.getOutputStream();
 } 
 catch (IOException streamError) { 
 Log.e(TAG, "Error when getting input or output Stream");
 }
 }

 public void run() {
 byte[] buffer = new byte[1024]; // buffer store for the stream
 int bytes; // bytes returned from read()

 // Keep listening to the InputStream until an exception occurs
 while (true) {
 try {
 // Read from the InputStream
 bytes = btInputStream.read(buffer);
 // Send the obtained bytes to the UI activity
 mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
 .sendToTarget();
 } 
 catch (IOException e) {
 Log.e(TAG, "Error reading from btInputStream");
 break;
 }
 }
 }

 /* Call this from the main activity to send data to the remote device */
 public void write(byte[] bytes) {
 try {
 btOutputStream.write(bytes);
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when writing to btOutputStream");
 }
 }

 /* Call this from the main activity to shutdown the connection */
 public void cancel() {
 try {
 btSocket.close();
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when closing the btSocket");
 }
 }
}

Notice that we place an endless loop in the run() method to continuously read bytes from the InputStream. This continuous process of reading bytes needs to be a different thread from the main application otherwise it would cause the program to "hang". This thread passes any read bytes to the main application by using the Handler's .sendToTarget() method.
You will also notice the use of Log.e(TAG, ".....") commands. This is useful for debugging Android problems, especially when you comae across errors that generate a "caused the application to close unexpectedly" dialog box to appear on your phone. I personally created a shortcut of the adb.exe on my desktop and changed the target to

"c:\[INSERT FOLDER]\Android\android-sdk\platform-tools\adb.exe" logcat *:E

The adb.exe program comes with the Android-SDK downloaded in Part One . Once you find the adb.exe on your hard-drive, you just create a shortcut on your desktop. Right-click the shortcut, choose "Properties" and as indicated above, you change the last bit of the Target to

logcat *:E

So if you get an unexpected error on your android device, just go back to your laptop, and double-click on your new desktop adb.exe shortcut to get a better idea of where your program has gone wrong.

We will now incorporate the sketch above into our ConnectBluetooth Android/Processing App, however we will call this updated version "SendReceiveBytes"
Once we have created a successful connection, and created our Input/OutputStreams, we will send a single letter "r" to the Arduino via bluetooth, and if all goes well, we should see the light on the RGB Chainable LED turn Red (see further down for Arduino sketch).
I borrowed Byron's code snippet from this site: to convert a string ("r") to a byte array, which is used in the write() method. The relevant code can be found on lines 199-208 below. I have bolded the lines numbers to make it a little easier to see the changes I made (compared to the previous sketch).

Android/Processing Sketch 6: SendReceiveBytes

/* SendReceiveBytes: Written by ScottC on 25 March 2013 using 
 Processing version 2.0b8
 Tested on a Samsung Galaxy SII, with Android version 2.3.4
 Android ADK - API 10 SDK platform */

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;
import android.view.Gravity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

import java.util.UUID;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
public BluetoothSocket scSocket;


boolean foundDevice=false; //When true, the screen turns green.
boolean BTisConnected=false; //When true, the screen turns purple.
String serverName = "ArduinoBasicsServer";

// Message types used by the Handler
public static final int MESSAGE_WRITE = 1;
public static final int MESSAGE_READ = 2;
String readMessage="";

//Get the default Bluetooth adapter
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();

/*The startActivityForResult() within setup() launches an 
 Activity which is used to request the user to turn Bluetooth on. 
 The following onActivityResult() method is called when this 
 Activity exits. */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 if (requestCode==0) {
 if (resultCode == RESULT_OK) {
 ToastMaster("Bluetooth has been switched ON");
 } 
 else {
 ToastMaster("You need to turn Bluetooth ON !!!");
 }
 }
}


/* Create a BroadcastReceiver that will later be used to 
 receive the names of Bluetooth devices in range. */
BroadcastReceiver myDiscoverer = new myOwnBroadcastReceiver();


/* Create a BroadcastReceiver that will later be used to
 identify if the Bluetooth device is connected */
BroadcastReceiver checkIsConnected = new myOwnBroadcastReceiver();


// The Handler that gets information back from the Socket
private final Handler mHandler = new Handler() {
 @Override
 public void handleMessage(Message msg) {
 switch (msg.what) {
 case MESSAGE_WRITE:
 //Do something when writing
 break;
 case MESSAGE_READ:
 //Get the bytes from the msg.obj
 byte[] readBuf = (byte[]) msg.obj;
 // construct a string from the valid bytes in the buffer
 readMessage = new String(readBuf, 0, msg.arg1);
 break;
 }
 }
};


void setup() {
 orientation(LANDSCAPE);
 /*IF Bluetooth is NOT enabled, then ask user permission to enable it */
 if (!bluetooth.isEnabled()) {
 Intent requestBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(requestBluetooth, 0);
 }


 /*If Bluetooth is now enabled, then register a broadcastReceiver to report any
 discovered Bluetooth devices, and then start discovering */
 if (bluetooth.isEnabled()) {
 registerReceiver(myDiscoverer, new IntentFilter(BluetoothDevice.ACTION_FOUND));
 registerReceiver(checkIsConnected, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));

 //Start bluetooth discovery if it is not doing so already
 if (!bluetooth.isDiscovering()) {
 bluetooth.startDiscovery();
 }
 }
}


void draw() {
 //Display a green screen if a device has been found,
 //Display a purple screen when a connection is made to the device
 if (foundDevice) {
 if (BTisConnected) {
 background(170, 50, 255); // purple screen
 }
 else {
 background(10, 255, 10); // green screen
 }
 }

 //Display anything received from Arduino
 text(readMessage, 10, 10);
}


/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 ConnectToBluetooth connectBT;

 @Override
 public void onReceive(Context context, Intent intent) {
 String action=intent.getAction();
 ToastMaster("ACTION:" + action);

 //Notification that BluetoothDevice is FOUND
 if (BluetoothDevice.ACTION_FOUND.equals(action)) {
 //Display the name of the discovered device
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 ToastMaster("Discovered: " + discoveredDeviceName);

 //Display more information about the discovered device
 BluetoothDevice discoveredDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
 ToastMaster("getAddress() = " + discoveredDevice.getAddress());
 ToastMaster("getName() = " + discoveredDevice.getName());

 int bondyState=discoveredDevice.getBondState();
 ToastMaster("getBondState() = " + bondyState);

 String mybondState;
 switch(bondyState) {
 case 10: 
 mybondState="BOND_NONE";
 break;
 case 11: 
 mybondState="BOND_BONDING";
 break;
 case 12: 
 mybondState="BOND_BONDED";
 break;
 default: 
 mybondState="INVALID BOND STATE";
 break;
 }
 ToastMaster("getBondState() = " + mybondState);

 //Change foundDevice to true which will make the screen turn green
 foundDevice=true;

 //Connect to the discovered bluetooth device (SeeedBTSlave)
 if (discoveredDeviceName.equals("SeeedBTSlave")) {
 ToastMaster("Connecting you Now !!");
 unregisterReceiver(myDiscoverer);
 connectBT = new ConnectToBluetooth(discoveredDevice);
 //Connect to the the device in a new thread
 new Thread(connectBT).start();
 }
 }

 //Notification if bluetooth device is connected
 if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
 ToastMaster("CONNECTED _ YAY");

 while (scSocket==null) {
 //do nothing
 }
 ToastMaster("scSocket" + scSocket);
 BTisConnected=true; //turn screen purple 
 if (scSocket!=null) {
 SendReceiveBytes sendReceiveBT = new SendReceiveBytes(scSocket);
 new Thread(sendReceiveBT).start();
 String red = "r";
 byte[] myByte = stringToBytesUTFCustom(red);
 sendReceiveBT.write(myByte);
 }
 }
 }
}
public static byte[] stringToBytesUTFCustom(String str) {
 char[] buffer = str.toCharArray();
 byte[] b = new byte[buffer.length << 1];
 for (int i = 0; i < buffer.length; i++) {
 int bpos = i << 1;
 b[bpos] = (byte) ((buffer[i]&0xFF00)>>8);
 b[bpos + 1] = (byte) (buffer[i]&0x00FF);
 }
 return b;
}

public class ConnectToBluetooth implements Runnable {
 private BluetoothDevice btShield;
 private BluetoothSocket mySocket = null;
 private UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

 public ConnectToBluetooth(BluetoothDevice bluetoothShield) {
 btShield = bluetoothShield;
 try {
 mySocket = btShield.createRfcommSocketToServiceRecord(uuid);
 }
 catch(IOException createSocketException) {
 //Problem with creating a socket
 Log.e("ConnectToBluetooth", "Error with Socket");
 }
 }

 @Override
 public void run() {
 /* Cancel discovery on Bluetooth Adapter to prevent slow connection */
 bluetooth.cancelDiscovery();

 try {
 /*Connect to the bluetoothShield through the Socket. This will block
 until it succeeds or throws an IOException */
 mySocket.connect();
 scSocket=mySocket;
 } 
 catch (IOException connectException) {
 Log.e("ConnectToBluetooth", "Error with Socket Connection");
 try {
 mySocket.close(); //try to close the socket
 }
 catch(IOException closeException) {
 }
 return;
 }
 }

 /* Will cancel an in-progress connection, and close the socket */
 public void cancel() {
 try {
 mySocket.close();
 } 
 catch (IOException e) {
 }
 }
}


private class SendReceiveBytes implements Runnable {
 private BluetoothSocket btSocket;
 private InputStream btInputStream = null;
 private OutputStream btOutputStream = null;
 String TAG = "SendReceiveBytes";

 public SendReceiveBytes(BluetoothSocket socket) {
 btSocket = socket;
 try {
 btInputStream = btSocket.getInputStream();
 btOutputStream = btSocket.getOutputStream();
 } 
 catch (IOException streamError) { 
 Log.e(TAG, "Error when getting input or output Stream");
 }
 }


 public void run() {
 byte[] buffer = new byte[1024]; // buffer store for the stream
 int bytes; // bytes returned from read()

 // Keep listening to the InputStream until an exception occurs
 while (true) {
 try {
 // Read from the InputStream
 bytes = btInputStream.read(buffer);
 // Send the obtained bytes to the UI activity
 mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
 .sendToTarget();
 } 
 catch (IOException e) {
 Log.e(TAG, "Error reading from btInputStream");
 break;
 }
 }
 }


 /* Call this from the main activity to send data to the remote device */
 public void write(byte[] bytes) {
 try {
 btOutputStream.write(bytes);
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when writing to btOutputStream");
 }
 }


 /* Call this from the main activity to shutdown the connection */
 public void cancel() {
 try {
 btSocket.close();
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when closing the btSocket");
 }
 }
}



/* My ToastMaster function to display a messageBox on the screen */
void ToastMaster(String textToDisplay) {
 Toast myMessage = Toast.makeText(getApplicationContext(), 
 textToDisplay, 
 Toast.LENGTH_SHORT);
 myMessage.setGravity(Gravity.CENTER, 0, 0);
 myMessage.show();
}

Arduino Sketch: Testing the Input/OutputStream

We will borrow the Arduino Sketch from my previous blog post (here). Which should change the RGB LED to red when it receives an "r" through the bluetooth serial port.
You should also be able to send text to the Android phone by opening up the Serial Monitor on the Arduino IDE (although found this to be somewhat unreliable/unpredictable. I may need to investigate a better way of doing this, but it should work to some capacity (I sometimes find that a couple of letters go missing on transmision).

In this sketch I am using a Bluetooth shield like this one, and have connected a Grove Chainable RGB LED to it using a Grove Universal 4 Pin Cable.

Arduino Sketch 2: Bluetooth RGB Colour Changer

/* This project combines the code from a few different sources.
This project was put together by ScottC on the 15/01/2013
http://arduinobasics.blogspot.com/

Bluetooth slave code by Steve Chang - downloaded from :
http://www.seeedstudio.com/wiki/index.php?title=Bluetooth_Shield

Grove Chainable RGB code can be found here :
http://www.seeedstudio.com/wiki/Grove_-_Chainable_RGB_LED#Introduction

*/
 
#include <SoftwareSerial.h> //Software Serial Port
#define uint8 unsigned char 
#define uint16 unsigned int
#define uint32 unsigned long int

#define RxD 6 // This is the pin that the Bluetooth (BT_TX) will transmit to the Arduino (RxD)
#define TxD 7 // This is the pin that the Bluetooth (BT_RX) will receive from the Arduino (TxD)
 
#define DEBUG_ENABLED 1

int Clkpin = 9; //RGB LED Clock Pin (Digital 9)
int Datapin = 8; //RGB LED Data Pin (Digital 8)
 
SoftwareSerial blueToothSerial(RxD,TxD);
/*----------------------SETUP----------------------------*/ void setup() { 
 Serial.begin(9600); // Allow Serial communication via USB cable to computer (if required)
 pinMode(RxD, INPUT); // Setup the Arduino to receive INPUT from the bluetooth shield on Digital Pin 6
 pinMode(TxD, OUTPUT); // Setup the Arduino to send data (OUTPUT) to the bluetooth shield on Digital Pin 7
 pinMode(13,OUTPUT); // Use onboard LED if required.
 setupBlueToothConnection(); //Used to initialise the Bluetooth shield
 
 pinMode(Datapin, OUTPUT); // Setup the RGB LED Data Pin
 pinMode(Clkpin, OUTPUT); // Setup the RGB LED Clock pin
 
} 
/*----------------------LOOP----------------------------*/ void loop() { 
 digitalWrite(13,LOW); //Turn off the onboard Arduino LED
 char recvChar;
 while(1){
 if(blueToothSerial.available()){//check if there's any data sent from the remote bluetooth shield
 recvChar = blueToothSerial.read();
 Serial.print(recvChar); // Print the character received to the Serial Monitor (if required)
 
 //If the character received = 'r' , then change the RGB led to display a RED colour
 if(recvChar=='r'){
 Send32Zero(); // begin
 DataDealWithAndSend(255, 0, 0); // first node data
 Send32Zero(); // send to update data 
 }
 
 //If the character received = 'g' , then change the RGB led to display a GREEN colour
 if(recvChar=='g'){
 Send32Zero(); // begin
 DataDealWithAndSend(0, 255, 0); // first node data
 Send32Zero(); // send to update data 
 }
 
 //If the character received = 'b' , then change the RGB led to display a BLUE colour
 if(recvChar=='b'){
 Send32Zero(); // begin
 DataDealWithAndSend(0, 0, 255); // first node data
 Send32Zero(); // send to update data 
 }
 }
 
 //You can use the following code to deal with any information coming from the Computer (serial monitor)
 if(Serial.available()){
 recvChar = Serial.read();
 
 //This will send value obtained (recvChar) to the phone. The value will be displayed on the phone.
 blueToothSerial.print(recvChar);
 }
 }
} 

//The following code is necessary to setup the bluetooth shield ------copy and paste----------------
void setupBlueToothConnection()
{
 blueToothSerial.begin(38400); //Set BluetoothBee BaudRate to default baud rate 38400
 blueToothSerial.print("\r\n+STWMOD=0\r\n"); //set the bluetooth work in slave mode
 blueToothSerial.print("\r\n+STNA=SeeedBTSlave\r\n"); //set the bluetooth name as "SeeedBTSlave"
 blueToothSerial.print("\r\n+STOAUT=1\r\n"); // Permit Paired device to connect me
 blueToothSerial.print("\r\n+STAUTO=0\r\n"); // Auto-connection should be forbidden here
 delay(2000); // This delay is required.
 blueToothSerial.print("\r\n+INQ=1\r\n"); //make the slave bluetooth inquirable 
 Serial.println("The slave bluetooth is inquirable!");
 delay(2000); // This delay is required.
 blueToothSerial.flush();
}

//The following code snippets are used update the colour of the RGB LED-----copy and paste------------
void ClkProduce(void){
 digitalWrite(Clkpin, LOW);
 delayMicroseconds(20); 
 digitalWrite(Clkpin, HIGH);
 delayMicroseconds(20); 
}
 void Send32Zero(void){
 unsigned char i;
 for (i=0; i<32; i++){
 digitalWrite(Datapin, LOW);
 ClkProduce();
 }
}
 
uint8 TakeAntiCode(uint8 dat){
 uint8 tmp = 0;
 if ((dat & 0x80) == 0){
 tmp |= 0x02; 
 }
 
 if ((dat & 0x40) == 0){
 tmp |= 0x01; 
 }
 
 return tmp;
}
 // gray data
void DatSend(uint32 dx){
 uint8 i;
 for (i=0; i<32; i++){
 if ((dx & 0x80000000) != 0){
 digitalWrite(Datapin, HIGH);
 } else {
 digitalWrite(Datapin, LOW);
 }
 
 dx <<= 1;
 ClkProduce();
 }
}
 // data processing
void DataDealWithAndSend(uint8 r, uint8 g, uint8 b){
 uint32 dx = 0;
 
 dx |= (uint32)0x03 << 30; // highest two bits 1，flag bits
 dx |= (uint32)TakeAntiCode(b) << 28;
 dx |= (uint32)TakeAntiCode(g) << 26; 
 dx |= (uint32)TakeAntiCode(r) << 24;
 
 dx |= (uint32)b << 16;
 dx |= (uint32)g << 8;
 dx |= r;
 
 DatSend(dx);
}

Some GUI Buttons

My aim is to somewhat recreate the experience from a similar project I blogged about (here). However I wanted to have much more control over the GUI. I will start by creating a few buttons, but will later look at making a much more fun/interactive design (hopefully). The following simple Android/Processing sketch will be totally independant of the sketch above, it will be a simple App that will have a few buttons which will change the colour of the background on the phone. Once we get the hang of this, we will incorporate it into our Bluetooth Sketch.
To start off with, we will need to download an Android/Processing library which will allow us to create the buttons that we will use in our App.

You can get the APWidgets library (version r44) here

Unzip the apwidgets_r44.zip file and put the apwidgets folder into your default Processing sketch "libraries" folder. For more information about installing contributed libraries into you Processing IDE - have a look at this site.
You will need to reboot your Processing IDE before being able to see the "apwidgets" item appear in the Processing IDE's menu,

Sketch > Import Library : Under the "Contributed" list item.

If you cannot see this menu item, then you will need to try again. Make sure you are putting it into the default sketch libraries folder, which may not be in the same folder as the processing IDE. To find out the default sketch location - look here:

File > Preferences > Sketchbook location

Ok, now that you have the APWidgets library installed in your Processing IDE, make sure you are still in Andorid Mode, and copy the following sketch into the IDE, and run the program on your device. This sketch borrows heavily from the APWidgets Button example, which can be found here.

Android/Processing Sketch 7: Button Presser

import apwidgets.*;

APWidgetContainer widgetContainer; 
APButton redButton, greenButton, blueButton, offButton;
String buttonText="";
int buttonWidth=0;
int buttonHeight=0;
int n=4; //number of buttons
int gap=10; //gap between buttons


void setup() {
 buttonWidth=((width/n)-(n*gap));
 buttonHeight=(height/2);
 widgetContainer = new APWidgetContainer(this); //create new container for widgets
 redButton =new APButton((buttonWidth*(n-4)+(gap*1)), gap, buttonWidth, buttonHeight, "RED"); //Create a RED button
 greenButton = new APButton((buttonWidth*(n-3)+(gap*2)), gap, buttonWidth, buttonHeight, "GREEN"); //Create a GREEN button
 blueButton = new APButton((buttonWidth*(n-2)+(gap*3)), gap, buttonWidth, buttonHeight, "BLUE"); //Create a BLUE button
 offButton = new APButton((buttonWidth*(n-1)+(gap*4)), gap, buttonWidth, buttonHeight, "OFF"); //Create a OFF button
 widgetContainer.addWidget(redButton); //place red button in container
 widgetContainer.addWidget(greenButton); //place green button in container
 widgetContainer.addWidget(blueButton);//place blue button in container
 widgetContainer.addWidget(offButton);//place off button in container
 background(0); //Start with a black background
}



void draw() { 
 //Change the text based on the button being pressed.
 text(buttonText, 10, buttonHeight+(buttonHeight/2));
}



//onClickWidget is called when a widget is clicked/touched
void onClickWidget(APWidget widget) {

 if (widget == redButton) { //if the red button was clicked
 buttonText="RED";
 background(255, 0, 0);
 }
 else if (widget == greenButton) { //if the green button was clicked
 buttonText="GREEN";
 background(0, 255, 0);
 }
 else if (widget == blueButton) { //if the blue button was clicked
 buttonText="BLUE";
 background(0, 0, 255);
 }
 else if (widget == offButton) { //if the off button was clicked
 buttonText="OFF";
 background(0);
 }
}

The sketch creates 4 buttons, one for Red, Green, Blue and Off. In this example, we use the onClickWidget() method to deal with button_click events, which we use to change the colour of the background. I forgot to include the following line in the setup() method:

orientation(LANDSCAPE);

This will force the application to go into landscape mode, which is what I intended.

Bluetooth Buttons : Adding Buttons to the Bluetooth project

We will now incorporate the Buttons sketch into our Bluetooth project so that when we press a button, it will send a letter to the Arduino via Bluetooth. The letter will be used by the Arduino to decide what colour to display on the Chainable RGB LED. We will still keep the previous functionality of changing the LED to RED when a successful Input/OutputStream is created, because this will be the signal to suggest that it is now ok to press the buttons (and we should see it work).

Here is the updated Android/Processing sketch

Android/Processing Sketch 8: Bluetooth App1

/* BluetoothApp1: Written by ScottC on 25 March 2013 using 
 Processing version 2.0b8
 Tested on a Samsung Galaxy SII, with Android version 2.3.4
 Android ADK - API 10 SDK platform
 Apwidgets version: r44 */

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;
import android.view.Gravity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

import java.util.UUID;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import apwidgets.*;
public BluetoothSocket scSocket;


//Used for the GUI**************************************
APWidgetContainer widgetContainer; 
APButton redButton, greenButton, blueButton, offButton;
String buttonText="";
int buttonWidth=0;
int buttonHeight=0;
int n=4; //number of buttons
int gap=10; //gap between buttons

boolean foundDevice=false; //When true, the screen turns green.
boolean BTisConnected=false; //When true, the screen turns purple.
String serverName = "ArduinoBasicsServer";

// Message types used by the Handler
public static final int MESSAGE_WRITE = 1;
public static final int MESSAGE_READ = 2;
String readMessage="";

//Used to send bytes to the Arduino
SendReceiveBytes sendReceiveBT=null;

//Get the default Bluetooth adapter
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();

/*The startActivityForResult() within setup() launches an 
 Activity which is used to request the user to turn Bluetooth on. 
 The following onActivityResult() method is called when this 
 Activity exits. */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 if (requestCode==0) {
 if (resultCode == RESULT_OK) {
 ToastMaster("Bluetooth has been switched ON");
 } 
 else {
 ToastMaster("You need to turn Bluetooth ON !!!");
 }
 }
}


/* Create a BroadcastReceiver that will later be used to 
 receive the names of Bluetooth devices in range. */
BroadcastReceiver myDiscoverer = new myOwnBroadcastReceiver();


/* Create a BroadcastReceiver that will later be used to
 identify if the Bluetooth device is connected */
BroadcastReceiver checkIsConnected = new myOwnBroadcastReceiver();



// The Handler that gets information back from the Socket
private final Handler mHandler = new Handler() {
 @Override
 public void handleMessage(Message msg) {
 switch (msg.what) {
 case MESSAGE_WRITE:
 //Do something when writing
 break;
 case MESSAGE_READ:
 //Get the bytes from the msg.obj
 byte[] readBuf = (byte[]) msg.obj;
 // construct a string from the valid bytes in the buffer
 readMessage = new String(readBuf, 0, msg.arg1);
 break;
 }
 }
};



void setup() {
 orientation(LANDSCAPE);

 //Setup GUI********************************
 buttonWidth=((width/n)-(n*gap));
 buttonHeight=(height/2);
 widgetContainer = new APWidgetContainer(this); //create new container for widgets
 redButton =new APButton((buttonWidth*(n-4)+(gap*1)), gap, buttonWidth, buttonHeight, "RED"); //Create a RED button
 greenButton = new APButton((buttonWidth*(n-3)+(gap*2)), gap, buttonWidth, buttonHeight, "GREEN"); //Create a GREEN button
 blueButton = new APButton((buttonWidth*(n-2)+(gap*3)), gap, buttonWidth, buttonHeight, "BLUE"); //Create a BLUE button
 offButton = new APButton((buttonWidth*(n-1)+(gap*4)), gap, buttonWidth, buttonHeight, "OFF"); //Create a OFF button
 widgetContainer.addWidget(redButton); //place red button in container
 widgetContainer.addWidget(greenButton); //place green button in container
 widgetContainer.addWidget(blueButton);//place blue button in container
 widgetContainer.addWidget(offButton);//place off button in container
 background(0); //Start with a black background

 /*IF Bluetooth is NOT enabled, then ask user permission to enable it */
 if (!bluetooth.isEnabled()) {
 Intent requestBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(requestBluetooth, 0);
 }

 /*If Bluetooth is now enabled, then register a broadcastReceiver to report any
 discovered Bluetooth devices, and then start discovering */
 if (bluetooth.isEnabled()) {
 registerReceiver(myDiscoverer, new IntentFilter(BluetoothDevice.ACTION_FOUND));
 registerReceiver(checkIsConnected, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));

 //Start bluetooth discovery if it is not doing so already
 if (!bluetooth.isDiscovering()) {
 bluetooth.startDiscovery();
 }
 }
}


void draw() {
 //Display a green screen if a device has been found,
 //Display a purple screen when a connection is made to the device
 if (foundDevice) {
 if (BTisConnected) {
 background(170, 50, 255); // purple screen
 }
 else {
 background(10, 255, 10); // green screen
 }
 }


 //Change the text based on the button being pressed.
 text(buttonText, 10, buttonHeight+(buttonHeight/2));

 //Display anything received from Arduino
 text(readMessage, 10, buttonHeight+(buttonHeight/2)+30);
}



/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 ConnectToBluetooth connectBT;

 @Override
 public void onReceive(Context context, Intent intent) {
 String action=intent.getAction();
 ToastMaster("ACTION:" + action);

 //Notification that BluetoothDevice is FOUND
 if (BluetoothDevice.ACTION_FOUND.equals(action)) {
 //Display the name of the discovered device
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 ToastMaster("Discovered: " + discoveredDeviceName);

 //Display more information about the discovered device
 BluetoothDevice discoveredDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
 ToastMaster("getAddress() = " + discoveredDevice.getAddress());
 ToastMaster("getName() = " + discoveredDevice.getName());

 int bondyState=discoveredDevice.getBondState();
 ToastMaster("getBondState() = " + bondyState);

 String mybondState;
 switch(bondyState) {
 case 10: 
 mybondState="BOND_NONE";
 break;
 case 11: 
 mybondState="BOND_BONDING";
 break;
 case 12: 
 mybondState="BOND_BONDED";
 break;
 default: 
 mybondState="INVALID BOND STATE";
 break;
 }
 ToastMaster("getBondState() = " + mybondState);

 //Change foundDevice to true which will make the screen turn green
 foundDevice=true;

 //Connect to the discovered bluetooth device (SeeedBTSlave)
 if (discoveredDeviceName.equals("SeeedBTSlave")) {
 ToastMaster("Connecting you Now !!");
 unregisterReceiver(myDiscoverer);
 connectBT = new ConnectToBluetooth(discoveredDevice);
 //Connect to the the device in a new thread
 new Thread(connectBT).start();
 }
 }

 //Notification if bluetooth device is connected
 if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
 ToastMaster("CONNECTED _ YAY");
 int counter=0;
 while (scSocket==null) {
 //do nothing
 }
 ToastMaster("scSocket" + scSocket);
 BTisConnected=true; //turn screen purple 
 if (scSocket!=null) {
 sendReceiveBT = new SendReceiveBytes(scSocket);
 new Thread(sendReceiveBT).start();
 String red = "r";
 byte[] myByte = stringToBytesUTFCustom(red);
 sendReceiveBT.write(myByte);
 }
 }
 }
}

public static byte[] stringToBytesUTFCustom(String str) {
 char[] buffer = str.toCharArray();
 byte[] b = new byte[buffer.length << 1];
 for (int i = 0; i < buffer.length; i++) {
 int bpos = i << 1;
 b[bpos] = (byte) ((buffer[i]&0xFF00)>>8);
 b[bpos + 1] = (byte) (buffer[i]&0x00FF);
 }
 return b;
}

public class ConnectToBluetooth implements Runnable {
 private BluetoothDevice btShield;
 private BluetoothSocket mySocket = null;
 private UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

 public ConnectToBluetooth(BluetoothDevice bluetoothShield) {
 btShield = bluetoothShield;
 try {
 mySocket = btShield.createRfcommSocketToServiceRecord(uuid);
 }
 catch(IOException createSocketException) {
 //Problem with creating a socket
 Log.e("ConnectToBluetooth", "Error with Socket");
 }
 }

 @Override
 public void run() {
 /* Cancel discovery on Bluetooth Adapter to prevent slow connection */
 bluetooth.cancelDiscovery();

 try {
 /*Connect to the bluetoothShield through the Socket. This will block
 until it succeeds or throws an IOException */
 mySocket.connect();
 scSocket=mySocket;
 } 
 catch (IOException connectException) {
 Log.e("ConnectToBluetooth", "Error with Socket Connection");
 try {
 mySocket.close(); //try to close the socket
 }
 catch(IOException closeException) {
 }
 return;
 }
 }

 // Will allow you to get the socket from this class
 public BluetoothSocket getSocket() {
 return mySocket;
 }

 /* Will cancel an in-progress connection, and close the socket */
 public void cancel() {
 try {
 mySocket.close();
 } 
 catch (IOException e) {
 }
 }
}



private class SendReceiveBytes implements Runnable {
 private BluetoothSocket btSocket;
 private InputStream btInputStream = null;
 ;
 private OutputStream btOutputStream = null;
 String TAG = "SendReceiveBytes";

 public SendReceiveBytes(BluetoothSocket socket) {
 btSocket = socket;
 try {
 btInputStream = btSocket.getInputStream();
 btOutputStream = btSocket.getOutputStream();
 } 
 catch (IOException streamError) { 
 Log.e(TAG, "Error when getting input or output Stream");
 }
 }

 public void run() {
 byte[] buffer = new byte[1024]; // buffer store for the stream
 int bytes; // bytes returned from read()

 // Keep listening to the InputStream until an exception occurs
 while (true) {
 try {
 // Read from the InputStream
 bytes = btInputStream.read(buffer);
 // Send the obtained bytes to the UI activity
 mHandler.obtainMessage(MESSAGE_READ, bytes, -1, buffer)
 .sendToTarget();
 } 
 catch (IOException e) {
 Log.e(TAG, "Error reading from btInputStream");
 break;
 }
 }
 }

 /* Call this from the main activity to send data to the remote device */
 public void write(byte[] bytes) {
 try {
 btOutputStream.write(bytes);
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when writing to btOutputStream");
 }
 }

 /* Call this from the main activity to shutdown the connection */
 public void cancel() {
 try {
 btSocket.close();
 } 
 catch (IOException e) { 
 Log.e(TAG, "Error when closing the btSocket");
 }
 }
}



/* My ToastMaster function to display a messageBox on the screen */
void ToastMaster(String textToDisplay) {
 Toast myMessage = Toast.makeText(getApplicationContext(), 
 textToDisplay, 
 Toast.LENGTH_SHORT);
 myMessage.setGravity(Gravity.CENTER, 0, 0);
 myMessage.show();
}




//onClickWidget is called when a widget is clicked/touched
void onClickWidget(APWidget widget) {
 String sendLetter = "";

 //Disable the previous Background colour changers
 foundDevice=false;
 BTisConnected=false;

 if (widget == redButton) { //if the red button was clicked
 buttonText="RED";
 background(255, 0, 0);
 sendLetter = "r";
 }
 else if (widget == greenButton) { //if the green button was clicked
 buttonText="GREEN";
 background(0, 255, 0);
 sendLetter = "g";
 }
 else if (widget == blueButton) { //if the blue button was clicked
 buttonText="BLUE";
 background(0, 0, 255);
 sendLetter = "b";
 }
 else if (widget == offButton) { //if the off button was clicked
 buttonText="OFF";
 background(0);
 sendLetter = "x";
 }

 byte[] myByte = stringToBytesUTFCustom(sendLetter);
 sendReceiveBT.write(myByte);
}

The sketch above has been thrown together without much planning or consideration for code efficiency. It was deliberately done this way so that you could see and follow the incremental approach used to create this Android/Processing Bluetooth App. I will do my best to rewrite and simplify some of the code, however, I don't anticipate the final sketch will be a short script.

You should have noticed that I included a fourth button called an "off" button. This will turn off the RGB led. However, the Arduino code in its current format does not know what to do with an 'x'. So we will update the sketch as follows:

Arduino Sketch 3: Bluetooth RGB Colour Changer (with OFF option)

/* This project combines the code from a few different sources.
 This project was put together by ScottC on the 15/01/2013
 http://arduinobasics.blogspot.com/
 
 Bluetooth slave code by Steve Chang - downloaded from :
 http://www.seeedstudio.com/wiki/index.php?title=Bluetooth_Shield
 
 Grove Chainable RGB code can be found here :
 http://www.seeedstudio.com/wiki/Grove_-_Chainable_RGB_LED#Introduction
 
 Updated on 25 March 2013: Receive 'x' to turn off RGB LED.
 
 */

#include <SoftwareSerial.h> //Software Serial Port

#define uint8 unsigned char 
#define uint16 unsigned int
#define uint32 unsigned long int

#define RxD 6 // This is the pin that the Bluetooth (BT_TX) will transmit to the Arduino (RxD)
#define TxD 7 // This is the pin that the Bluetooth (BT_RX) will receive from the Arduino (TxD)

#define DEBUG_ENABLED 1

int Clkpin = 9; //RGB LED Clock Pin (Digital 9)
int Datapin = 8; //RGB LED Data Pin (Digital 8)

SoftwareSerial blueToothSerial(RxD, TxD);


/*----------------------SETUP----------------------------*/
void setup() { 
 Serial.begin(9600); // Allow Serial communication via USB cable to computer (if required)
 pinMode(RxD, INPUT); // Setup the Arduino to receive INPUT from the bluetooth shield on Digital Pin 6
 pinMode(TxD, OUTPUT); // Setup the Arduino to send data (OUTPUT) to the bluetooth shield on Digital Pin 7
 pinMode(13, OUTPUT); // Use onboard LED if required.
 setupBlueToothConnection(); //Used to initialise the Bluetooth shield

 pinMode(Datapin, OUTPUT); // Setup the RGB LED Data Pin
 pinMode(Clkpin, OUTPUT); // Setup the RGB LED Clock pin
} 


/*----------------------LOOP----------------------------*/
void loop() { 
 digitalWrite(13, LOW); //Turn off the onboard Arduino LED
 char recvChar;
 while (1) {
 if (blueToothSerial.available()) {//check if there's any data sent from the remote bluetooth shield
 recvChar = blueToothSerial.read();
 Serial.print(recvChar); // Print the character received to the Serial Monitor (if required)

 //If the character received = 'r' , then change the RGB led to display a RED colour
 if (recvChar=='r') {
 Send32Zero(); // begin
 DataDealWithAndSend(255, 0, 0); // first node data
 Send32Zero(); // send to update data
 }

 //If the character received = 'g' , then change the RGB led to display a GREEN colour
 if (recvChar=='g') {
 Send32Zero(); // begin
 DataDealWithAndSend(0, 255, 0); // first node data
 Send32Zero(); // send to update data
 }

 //If the character received = 'b' , then change the RGB led to display a BLUE colour
 if (recvChar=='b') {
 Send32Zero(); // begin
 DataDealWithAndSend(0, 0, 255); // first node data
 Send32Zero(); // send to update data
 }

 //If the character received = 'x' , then turn RGB led OFF
 if (recvChar=='x') {
 Send32Zero(); // begin
 DataDealWithAndSend(0, 0, 0); // first node data
 Send32Zero(); // send to update data
 }
 }

 //You can use the following code to deal with any information coming from the Computer (serial monitor)
 if (Serial.available()) {
 recvChar = Serial.read();

 //This will send value obtained (recvChar) to the phone. The value will be displayed on the phone.
 blueToothSerial.print(recvChar);
 }
 }
} 



//The following code is necessary to setup the bluetooth shield ------copy and paste----------------
void setupBlueToothConnection()
{
 blueToothSerial.begin(38400); //Set BluetoothBee BaudRate to default baud rate 38400
 blueToothSerial.print("\r\n+STWMOD=0\r\n"); //set the bluetooth work in slave mode
 blueToothSerial.print("\r\n+STNA=SeeedBTSlave\r\n"); //set the bluetooth name as "SeeedBTSlave"
 blueToothSerial.print("\r\n+STOAUT=1\r\n"); // Permit Paired device to connect me
 blueToothSerial.print("\r\n+STAUTO=0\r\n"); // Auto-connection should be forbidden here
 delay(2000); // This delay is required.
 blueToothSerial.print("\r\n+INQ=1\r\n"); //make the slave bluetooth inquirable 
 Serial.println("The slave bluetooth is inquirable!");
 delay(2000); // This delay is required.
 blueToothSerial.flush();
}


//The following code snippets are used update the colour of the RGB LED-----copy and paste------------
void ClkProduce(void) {
 digitalWrite(Clkpin, LOW);
 delayMicroseconds(20); 
 digitalWrite(Clkpin, HIGH);
 delayMicroseconds(20);
}
void Send32Zero(void) {
 unsigned char i;
 for (i=0; i<32; i++) {
 digitalWrite(Datapin, LOW);
 ClkProduce();
 }
}



uint8 TakeAntiCode(uint8 dat) {
 uint8 tmp = 0;
 if ((dat & 0x80) == 0) {
 tmp |= 0x02;
 }

 if ((dat & 0x40) == 0) {
 tmp |= 0x01;
 }
 return tmp;
}


// gray data
void DatSend(uint32 dx) {
 uint8 i;
 for (i=0; i<32; i++) {
 if ((dx & 0x80000000) != 0) {
 digitalWrite(Datapin, HIGH);
 } 
 else {
 digitalWrite(Datapin, LOW);
 }
 dx <<= 1;
 ClkProduce();
 }
}

// data processing
void DataDealWithAndSend(uint8 r, uint8 g, uint8 b) {
 uint32 dx = 0;

 dx |= (uint32)0x03 << 30; // highest two bits 1，flag bits
 dx |= (uint32)TakeAntiCode(b) << 28;
 dx |= (uint32)TakeAntiCode(g) << 26; 
 dx |= (uint32)TakeAntiCode(r) << 24;

 dx |= (uint32)b << 16;
 dx |= (uint32)g << 8;
 dx |= r;

 DatSend(dx);
}

Well that concludes part 3.
Part 4 is a summary of the finished project with videos, screenshots, parts used etc.
I hope you found this tutorial useful. I would love to receive any advice on how I could improve these tutorials (please put your recommendations in comments below).

Reason for this Project:
While there are quite a few people creating Android/Arduino projects, I have not been able to find many that show how these are being accomplished using the Android/Processing IDE, and even less on how they are using Bluetooth in their Android/Processing projects. I hope my piecing of information will spark some creative Bluetooth projects of your own.

PART 4: Navigate here.

ScottC 25 Mar 15:03

android arduino arduinobasics best arduino blog bluetooth inputstream led logcat outputstream processing project rgb

Bluetooth Android Processing 2

PART TWO

If you happened to land on this page and missed PART ONE, I would advise you go back and read that section first. You may get lost coming in half way through the story. This is what you'll find in part one.

Downloading and setting up the Android SDK
Downloading the Processing IDE
Setting up and preparing the Android device
Running through a couple of Processing/Android sketches on an Andoid phone.

In the last sketch we checked to see if Bluetooth was enabled, if not, we then asked for permission to turn it on. The screen would then display a different colour depending on the Bluetooth state. So let's keep on going,

ToastMaster - the master of all Toasts

I will now introduce you to Toast. What does "Toast" have to do with programming ? Toast is used by Android to quietly display little messages on the screen.
Have a look here for a a quick introduction to Toast, otherwise have a look at the Android Developers Toast information.

I will be creating my own method that relies on Toast to make the process of displaying messages easier. I have named this method: "ToastMaster".
A word of warning. Calling ToastMaster from within setup() will cause errorsin the DiscoverBluetooth sketch (further down this page).
This will not happen in every sketch, but the Discoverbluetooth sketch has subActivities which may cause some sort of conflict.. I did warn you.

Here is a quick look at my ToastMaster method (no need to compile this code):

/* My ToastMaster function to display a messageBox on the screen */
void ToastMaster(String textToDisplay){
 Toast myMessage = Toast.makeText(getApplicationContext(), 
 textToDisplay,
 Toast.LENGTH_LONG);
 myMessage.setGravity(Gravity.CENTER, 0, 0);
 myMessage.show();
}

Here is a breakdown of what this is doing:

Toast.makeText() - is used to construct the message to be displayed.
getApplicationContext() - gets a handle on the Application
textToDisplay - is obvious, this is the text you want to display.
Toast.LENGTH_LONG - is how long you want the message to displayed for. (or LENGTH_SHORT)
setGravity() - sets the message position on the screen, in this case I have chosen to center the text.
show() - is used to actually show the message.

Broadcast Receivers : Looking out for Bluetooth devices
To listen/look out for any Bluetooth devices that are within range, we need to create and register a Broadcast receiver.
When registering a BroadcastReceiver, you will need to tell the program what it is you are looking / listening out for. In our case we want to listen out for occasions whereby a Bluetooth device is FOUND. This is represented by:

BluetoothDevice.ACTION_FOUND - this is sent or broadcast when a Bluetooth device is found (when in discovery mode).

If a BluetoothDevice is found, then the designated BroadcastReceiver will be called. We make our own BroadcastReceiver in order to perform a task such as displaying the name of the discovered device on the phone. However, before you will find anything, you have to start Discovering. This is done by calling the startDiscovery() method of the default Bluetooth adapter.

Here are the relevant components:

BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();
BroadcastReceiver myDiscoverer = new myOwnBroadcastReceiver();
//Within Setup()
 if (bluetooth.isEnabled()) {
 registerReceiver(myDiscoverer, new IntentFilter(BluetoothDevice.ACTION_FOUND));
 if (!bluetooth.isDiscovering()){
 bluetooth.startDiscovery();
 }
 }

/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 
 //Display the name of the discovered device
 ToastMaster("Discovered: " + discoveredDeviceName);
 }
}

Discovering Bluetooth devices: putting it all together

You will notice that in the following sketch, we have to import a whole lot more. Which is why I have tried to break it down into bite size chunks, to help you digest it all. Now we will put it all together into a sketch which will

ask to turn Bluetooth ON if it happens to be disabled.
If you don't turn on Bluetooth, it will tell you that you need to turn it on.
If you turn on bluetooth (or if it was already on), it will try to discover any bluetooth devices in range. These devices need to be made "discoverable" before running this sketch.
If the phone finds a bluetooth device, it will display the name of the device and will change the background screen colour to GREEN.

Android/Processing Sketch 4: DiscoverBluetooth

/* DiscoverBluetooth: Written by ScottC on 18 March 2013 using 
 Processing version 2.0b8
 Tested on a Samsung Galaxy SII, with Android version 2.3.4
 Android ADK - API 10 SDK platform */

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;
import android.view.Gravity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

boolean foundDevice=false; //When this is true, the screen turns green.
//Get the default Bluetooth adapter
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();

/*The startActivityForResult() within setup() launches an 
 Activity which is used to request the user to turn Bluetooth on. 
 The following onActivityResult() method is called when this 
 Activity exits. */
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){
 if(requestCode==0){
 if(resultCode == RESULT_OK){
 ToastMaster("Bluetooth has been switched ON");
 } else {
 ToastMaster("You need to turn Bluetooth ON !!!");
 }
 }
}


/* Create a Broadcast Receiver that will later be used to 
 receive the names of Bluetooth devices in range. */
BroadcastReceiver myDiscoverer = new myOwnBroadcastReceiver();


void setup(){
 orientation(LANDSCAPE);
 /*IF Bluetooth is NOT enabled, then ask user permission to enable it */
 if (!bluetooth.isEnabled()) {
 Intent requestBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(requestBluetooth, 0);
 }
 
 /*If Bluetooth is now enabled, then register a broadcastReceiver to report any
 discovered Bluetooth devices, and then start discovering */
 if (bluetooth.isEnabled()) {
 registerReceiver(myDiscoverer, new IntentFilter(BluetoothDevice.ACTION_FOUND));
 //Start bluetooth discovery if it is not doing so already
 if (!bluetooth.isDiscovering()){
 bluetooth.startDiscovery();
 }
 }
}


void draw(){
 //Display a green screen if a device has been found
 if(foundDevice){
 background(10,255,10);
 }
}


/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 
 //Display the name of the discovered device
 ToastMaster("Discovered: " + discoveredDeviceName);
 
 //Change foundDevice to true which will make the screen turn green
 foundDevice=true;
 }
}


/* My ToastMaster function to display a messageBox on the screen */
void ToastMaster(String textToDisplay){
 Toast myMessage = Toast.makeText(getApplicationContext(), 
 textToDisplay,
 Toast.LENGTH_LONG);
 myMessage.setGravity(Gravity.CENTER, 0, 0);
 myMessage.show();
}

Upgrading the Broadcast Receiver : More Device info

Ok, we have the device name. But what other information can we collect from the device? You can call

intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

This will return the discovered BluetoothDevice, which can then be probed to find the following information.

.getName() = Which is a different way of getting the name of the BluetoothDevice.

.getAddress() = Returns the hardware address of the BluetoothDevice. eg. "00:11:22:AA:BB:CC"

.getBondState() = Returns an integer which describes the BondState of the BluetoothDevice

These are the three possible BondStates

Here is an updated version of the custom BroadcastReceiver class (myOwnBroadcastReceiver) from the DiscoverBluetooth sketch described above.

/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 
 //Display the name of the discovered device
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 ToastMaster("Discovered: " + discoveredDeviceName);
 
 //Display more information about the discovered device
 BluetoothDevice discoveredDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
 ToastMaster("getAddress() = " + discoveredDevice.getAddress());
 ToastMaster("getName() = " + discoveredDevice.getName());
 
 int bondyState=discoveredDevice.getBondState();
 ToastMaster("getBondState() = " + bondyState);
 
 String mybondState;
 switch(bondyState){
 case 10: mybondState="BOND_NONE";
 break;
 case 11: mybondState="BOND_BONDING";
 break;
 case 12: mybondState="BOND_BONDED";
 break;
 default: mybondState="INVALID BOND STATE";
 break;
 }
 ToastMaster("getBondState() = " + mybondState);
 
 //Change foundDevice to true which will make the screen turn green
 foundDevice=true;
 }
}

If you replace the old version of myOwnBroadcastReceiver with this one, you will know a little bit more about the devices discovered.

Connecting to the Bluetooth Device:
While we now have more information about the Bluetooth device, we don't really need it, and we will get rid of it by the end of the tutorial, however we will keep it here for the time being. In the next updated sketch we will be making a connection to the discovered device, and turning the background purple when the connection is made. In order to do this we will need to

Create a boolean variable to hold the connection status
Create and register a new BroadcastReceiver to notify us when a connection broadcast action has been received.
Create a new thread to handle the connection
Change the background screen colour when a successful connection has been made

First we need the boolean to hold the connection status:

boolean BTisConnected=false;

When the boolean is true, the screen will change to purple. The draw() method will be updated to accommodate this requirement.
Next we will create and register a new BroadcastReceiver, it is created using this:

BroadcastReceiver checkIsConnected = new myOwnBroadcastReceiver();

This broadcastreceiver will be used to notify us when a connection has been made. Therefore we need to register the (BluetoothDevice.ACTION_ACL_CONNECTED)
action with the BroadcastReceiver in the following way

registerReceiver(checkIsConnected, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));

We will need to update myOwnBroadcastReceiver() to be able to differentiate beween this action and the (BluetoothDevice.ACTION_FOUND) action used already. This is done by first getting the action from the intent variable described in the onReceive() method within myOwnBroadcastReceiver().

String action=intent.getAction();

We can differentiate the two actions using the following simplified code in myOwnBroadcastReceiver:

public class myOwnBroadcastReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 String action=intent.getAction();

 //Notification that BluetoothDevice is FOUND
 if(BluetoothDevice.ACTION_FOUND.equals(action)){
 foundDevice=true; //Change the screen to green
 }
 
 //Notification if bluetooth device is connected
 if(BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)){
 BTisConnected=true; //turn screen purple
 }
 }
}

Now that we can be notified about the connection made to the Bluetooth Device, lets go through the code required to make the connection. We will only connect if we have actually discovered a device, so we will put this code within the FOUND section of myOwnBroadcastReceiver.

 //Connect to the discovered bluetooth device (SeeedBTSlave)
 if(discoveredDeviceName.equals("SeeedBTSlave")){
 unregisterReceiver(myDiscoverer);
 ConnectToBluetooth connectBT = new ConnectToBluetooth(discoveredDevice);
 //Connect to the the device in a new thread
 new Thread(connectBT).start();
 } 
 }

We use the discoveredDeviceName variable to specifically target the Bluetooth device we wish to connect to. We then unregister the myDiscoverer BroadcastReceiver because we are going to stop discovering before we connect to the Bluetooth Device, plus if you don't, it will generate an error. We then pass our discovered device to a new Thread to connect to that device in the background. The class used to handle the connection is the "ConnectToBluetooth" class as displayed below:

We will cancelDiscovery() on the bluetooth Adapter to prevent a slow connection.
Also we will need to use a specific UUID as per below:

private UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

I have tried changing the UUID, but changing it to a different number prevented it from establishing a connection.
Before you can connect to the Bluetooth shield you need to use the UUID to create a BluetoothSocket.

mySocket = btShield.createRfcommSocketToServiceRecord(uuid);

Once you have the socket, you can then try to connect using:

mySocket.connect();

Make sure you have some way of closing the socket, this is done in the cancel() method.

public class ConnectToBluetooth implements Runnable{
 private BluetoothDevice btShield;
 private BluetoothSocket mySocket = null;
 private UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
 
 public ConnectToBluetooth(BluetoothDevice bluetoothShield) {
 btShield = bluetoothShield;
 try{
 mySocket = btShield.createRfcommSocketToServiceRecord(uuid);
 }catch(IOException createSocketException){
 //Problem with creating a socket
 }
 }
 
 @Override
 public void run() {
 /* Cancel discovery on Bluetooth Adapter to prevent slow connection */
 bluetooth.cancelDiscovery();
 
 try{
 /*Connect to the bluetoothShield through the Socket. This will block
 until it succeeds or throws an IOException */
 mySocket.connect();
 } catch (IOException connectException){
 try{
 mySocket.close(); //try to close the socket
 }catch(IOException closeException){
 }
 return;
 }
 }
 
 /* Will cancel an in-progress connection, and close the socket */
 public void cancel() {
 try {
 mySocket.close();
 } catch (IOException e){
 }
 }
}

The major structure of this code was made possible using the following site:
http://jayxie.com/mirrors/android-sdk/guide/topics/wireless/bluetooth.html

And the following sites were also useful in getting some of the information I needed:
http://stackoverflow.com/questions/13238600/use-registerreceiver-for-non-activity-and-non-service-class
http://developer.android.com/guide/topics/connectivity/bluetooth.html

While I have described all the major components required to connect to the Bluetooth Device, I will now put it all together in a new and updated version of the "DiscoverBluetooth" Android/Processing sketch and call it "ConnectBluetooth". There is some additional code in this sketch which I did not specifically go through, for example, the code used to turn the background to purple in the draw() method. Look out for that one. Anyway, read through the following code, and make sure that you understand what each section is doing.

Android/Processing Sketch 5: ConnectBluetooth

/* ConnectBluetooth: Written by ScottC on 18 March 2013 using 
 Processing version 2.0b8
 Tested on a Samsung Galaxy SII, with Android version 2.3.4
 Android ADK - API 10 SDK platform */

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.widget.Toast;
import android.view.Gravity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

import java.util.UUID;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.util.Log;

import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;

boolean foundDevice=false; //When true, the screen turns green.
boolean BTisConnected=false; //When true, the screen turns purple.


//Get the default Bluetooth adapter
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();

/*The startActivityForResult() within setup() launches an 
 Activity which is used to request the user to turn Bluetooth on. 
 The following onActivityResult() method is called when this 
 Activity exits. */
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){
 if(requestCode==0){
 if(resultCode == RESULT_OK){
 ToastMaster("Bluetooth has been switched ON");
 } else {
 ToastMaster("You need to turn Bluetooth ON !!!");
 }
 }
}


/* Create a BroadcastReceiver that will later be used to 
 receive the names of Bluetooth devices in range. */
BroadcastReceiver myDiscoverer = new myOwnBroadcastReceiver();
/* Create a BroadcastReceiver that will later be used to
 identify if the Bluetooth device is connected */
BroadcastReceiver checkIsConnected = new myOwnBroadcastReceiver();

void setup(){
 orientation(LANDSCAPE);
 /*IF Bluetooth is NOT enabled, then ask user permission to enable it */
 if (!bluetooth.isEnabled()) {
 Intent requestBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(requestBluetooth, 0);
 }
 
 /*If Bluetooth is now enabled, then register a broadcastReceiver to report any
 discovered Bluetooth devices, and then start discovering */
 if (bluetooth.isEnabled()) {
 registerReceiver(myDiscoverer, new IntentFilter(BluetoothDevice.ACTION_FOUND));
 registerReceiver(checkIsConnected, new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));
 
 //Start bluetooth discovery if it is not doing so already
 if (!bluetooth.isDiscovering()){
 bluetooth.startDiscovery();
 }
 }
}


void draw(){
 //Display a green screen if a device has been found,
 //Display a purple screen when a connection is made to the device
 if(foundDevice){
 if(BTisConnected){
 background(170,50,255); // purple screen
 }else {
 background(10,255,10); // green screen
 }
 }
}


/* This BroadcastReceiver will display discovered Bluetooth devices */
public class myOwnBroadcastReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
 String action=intent.getAction();
 ToastMaster("ACTION:" + action);
 
 //Notification that BluetoothDevice is FOUND
 if(BluetoothDevice.ACTION_FOUND.equals(action)){
 //Display the name of the discovered device
 String discoveredDeviceName = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
 ToastMaster("Discovered: " + discoveredDeviceName);
 
 //Display more information about the discovered device
 BluetoothDevice discoveredDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
 ToastMaster("getAddress() = " + discoveredDevice.getAddress());
 ToastMaster("getName() = " + discoveredDevice.getName());
 
 int bondyState=discoveredDevice.getBondState();
 ToastMaster("getBondState() = " + bondyState);
 
 String mybondState;
 switch(bondyState){
 case 10: mybondState="BOND_NONE";
 break;
 case 11: mybondState="BOND_BONDING";
 break;
 case 12: mybondState="BOND_BONDED";
 break;
 default: mybondState="INVALID BOND STATE";
 break;
 }
 ToastMaster("getBondState() = " + mybondState);
 
 //Change foundDevice to true which will make the screen turn green
 foundDevice=true;
 
 //Connect to the discovered bluetooth device (SeeedBTSlave)
 if(discoveredDeviceName.equals("SeeedBTSlave")){
 ToastMaster("Connecting you Now !!");
 unregisterReceiver(myDiscoverer);
 ConnectToBluetooth connectBT = new ConnectToBluetooth(discoveredDevice);
 //Connect to the the device in a new thread
 new Thread(connectBT).start();
 } 
 }
 
 //Notification if bluetooth device is connected
 if(BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)){
 ToastMaster("CONNECTED _ YAY");
 BTisConnected=true; //turn screen purple
 }
 }
}
public class ConnectToBluetooth implements Runnable{
 private BluetoothDevice btShield;
 private BluetoothSocket mySocket = null;
 private UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
 
 public ConnectToBluetooth(BluetoothDevice bluetoothShield) {
 btShield = bluetoothShield;
 try{
 mySocket = btShield.createRfcommSocketToServiceRecord(uuid);
 }catch(IOException createSocketException){
 //Problem with creating a socket
 }
 }
 
 @Override
 public void run() {
 /* Cancel discovery on Bluetooth Adapter to prevent slow connection */
 bluetooth.cancelDiscovery();
 
 try{
 /*Connect to the bluetoothShield through the Socket. This will block
 until it succeeds or throws an IOException */
 mySocket.connect();
 } catch (IOException connectException){
 try{
 mySocket.close(); //try to close the socket
 }catch(IOException closeException){
 }
 return;
 }
 }
 
 /* Will cancel an in-progress connection, and close the socket */
 public void cancel() {
 try {
 mySocket.close();
 } catch (IOException e){
 }
 }
}

/* My ToastMaster function to display a messageBox on the screen */
void ToastMaster(String textToDisplay){
 Toast myMessage = Toast.makeText(getApplicationContext(), 
 textToDisplay,
 Toast.LENGTH_SHORT);
 myMessage.setGravity(Gravity.CENTER, 0, 0);
 myMessage.show();
}

The Arduino Sketch

Most of the Android/Processing code used so far has depended on a Bluetooth Device being discoverable. Our ultimate aim it to connect to a Bluetooth Shield on an Arduino UNO or compatible board such as the Freetronics Eleven. The following sketch was essentially taken from one of my previous posts (here), however, I have stripped it down to the bear essentials so that it will only be discoverable, and will not send or receive data. I will provide this functionality later. I just wanted to show you the essential bits to establish the connection to the Shield.

ARDUINO Sketch 1: Bluetooth Pair and Connect

/* This project combines the code from a few different sources.
This project was put together by ScottC on the 22/03/2013
http://arduinobasics.blogspot.com/

Bluetooth slave code by Steve Chang - downloaded from :
http://www.seeedstudio.com/wiki/index.php?title=Bluetooth_Shield

This sketch does nothing more than setup bluetooth 
connection capabilities. It does not send or receive data.

*/
 
#include <SoftwareSerial.h> //Software Serial Port

#define RxD 6 // This is the pin that the Bluetooth (BT_TX) will transmit to the Arduino (RxD)
#define TxD 7 // This is the pin that the Bluetooth (BT_RX) will receive from the Arduino (TxD)
 
#define DEBUG_ENABLED 1
 
SoftwareSerial blueToothSerial(RxD,TxD);
/*----------------------SETUP----------------------------*/ void setup() { 
 Serial.begin(9600); // Allow Serial communication via USB cable to computer (if required)
 pinMode(RxD, INPUT); // Setup the Arduino to receive INPUT from the bluetooth shield on Digital Pin 6
 pinMode(TxD, OUTPUT); // Setup the Arduino to send data (OUTPUT) to the bluetooth shield on Digital Pin 7
 pinMode(13,OUTPUT); // Use onboard LED if required.
 setupBlueToothConnection(); //Used to initialise the Bluetooth shield
} 
/*----------------------LOOP----------------------------*/ void loop() { 
 digitalWrite(13,LOW); //Turn off the onboard Arduino LED
 }
 
//The following code is necessary to setup the bluetooth shield ------copy and paste----------------
void setupBlueToothConnection()
{
 blueToothSerial.begin(38400); //Set BluetoothBee BaudRate to default baud rate 38400
 blueToothSerial.print("\r\n+STWMOD=0\r\n"); //set the bluetooth work in slave mode
 blueToothSerial.print("\r\n+STNA=SeeedBTSlave\r\n"); //set the bluetooth name as "SeeedBTSlave"
 blueToothSerial.print("\r\n+STOAUT=1\r\n"); // Permit Paired device to connect me
 blueToothSerial.print("\r\n+STAUTO=0\r\n"); // Auto-connection should be forbidden here
 delay(2000); // This delay is required.
 blueToothSerial.print("\r\n+INQ=1\r\n"); //make the slave bluetooth inquirable 
 Serial.println("The slave bluetooth is inquirable!");
 delay(2000); // This delay is required.
 blueToothSerial.flush();
}

Please make sure to setup the Bluetooth jumpers as per the picture below, otherwise you will not have much luck with the sketch above.

Well that brings us to the end of part TWO.

PART THREE
In part three we will attempt to actually send some data from the Android phone to the Arduino via Bluetooth, and vice versa. This will be when the real fun starts.

or GO BACK
Click on the link if you missed PART ONE

ScottC 18 Mar 18:29

android arduino arduinobasics best arduino blog bluetooth broadcastreceiver discover part two processing project toast tutorial

Bluetooth Android Processing 1

PART ONE

Introduction

This is a four part tutorial which will take you through step-by-step on how to create Android apps on your Mobile device that will allow you to communicate with your Arduino over Bluetooth. This tutorial is based upon the Windows environment and an Android device like the Samsung Galaxy S2 Phone.
I will take you through setting up your computer and phone, and will move through in stages so that you understand what each part of the bluetooth code is actually doing. Obviously you will need to ensure that you have a Bluetooth Shield on your Arduino to be able to walk through this tutorial with me.
If you are not interested in the step-by-step instructions, you can jump straight to the end (Part 4) which will have the complete Arduino and Android/Processing code that was used in the following video:

The Goal of this project (Video)

Setting up Processing for Android applications:
For the latest and most up to date version, please follow the instructions on this website: http://wiki.processing.org/w/Android

Step One:
Download the Android SDK from this website:
http://developer.android.com/sdk/index.html

Android SDK Download:
Make sure to select the "Use and Existing IDE" link, as per the picture below.

When you select the "Use an Existing IDE" link, it will then show you the appropriate download to use. This is what it should look like.

Select the "Download the SDK Tools for Windows" link.
Once you have downloaded the Android SDK, go ahead and install it as per the instructions below.
These instruction can also be found here.

Installing the necessary packages in the Android SDK Manager program
Make the following 3 selections:

Tools: Android SDK Platform-tools
API 10: SDK Platform
Extras: Google USB Driver

Then select the button on the bottom-right to install your selections.

Here is a picture of the Android SDK Manager selections:

While you may decide to download other packages,
you MUST download API 10: SDK Platform .
Do not leave this one out !!

Step Two: Processing Download
Download the latest Processing IDE(version 2.0 Beta 8) from this website:
http://processing.org/download/

I am using Windows 7, and have chosen to download the Windows 32 bit version as shown below.

Load Processing, and switch to Android mode, as per the image below.

You should now have an empty sketch window which looks something like this.

Step Three: Setting up the Android Hardware device (Phone)
For the latest steps you can have a look at this site:
http://developer.android.com/tools/device.html

However, these are the ones that I carried out:

Turn on USB debugging on your Android Phone:
To find out what Android Version you are on, have a look at
Settings > About Phone : look for heading "Android Version".

My Android version is 2.3.4 on my Samsung Galaxy S2.

To Enable USB Debugging:

Settings > Applications > Development > Select (or Enable) USB debugging

For those of you who have a different Android version, have a look below:

Downloading the USB driver for your Android Phone(Windows Users)
If you are developing on Windows and would like to connect an Android-powered device to test your applications, then you need to install the appropriate USB driver. Have a look at this site for more information on how to download the USB driver for your phone:
http://developer.android.com/tools/extras/oem-usb.html

I have a Samsung Galaxy S2 phone, so I had to go to the Samsung Site here:
http://www.samsung.com/us/support/downloads

But because I am not in the USA, I had to click on the link for "non-US products":
http://www.samsung.com/us/support/downloads/global

You will need the model number of your phone:
On the Samsung Galaxy S2, you can go into
Settings > About Phone => Model number. Otherwise, it is located behind the battery.

My Phone's Model Number is: GT-I9100

See the image below for the link to press if you have a non-US phone.

Then I continued with the install of the USB driver as per the document below:
http://developer.android.com/tools/extras/oem-usb.html

Step Four: Android-Processing Sketch

We will now test our our current setup and make sure that we can run a simple Processing Sketch on the Phone. Bluetooth functionality will be tested later on, so all we need for this step, is our computer, our Android phone, and a USB cable. While it is possible to run this sketch without an Android phone (by using the emulator), I personally do not have the patience to wait an eternity while the emulator boots up... (yes, it takes an eternity)... In this tutorial, we are going to test it on the device (phone).
This sketch has an orange background and a black circle which you can move around the screen with your finger (that's it) - I did say it was going to be a simple sketch.

Copy and paste the following Android-Processing sketch into the IDE, and then press the (Run on Device) button, which is the triangle button or press Ctrl-R.

Android/Processing Sketch 1: Circle Dragger

/*Circle Dragger: Simple Android-Processing Sketch written by ScottC on 13/03/2013.
 Visit: http://arduinobasics.blogspot.com/
*/
int circleWidth = 150;
void setup(){
 orientation(LANDSCAPE);
}
void draw(){
 background(255,100,0);
 fill(0);
 ellipse(mouseX,mouseY,circleWidth,circleWidth);
}

You should see an orange screen appear on your phone. Move your finger across the screen and watch as the black circle follows your finger.
No, not rocket science, but hopefully everything worked as planned. If you want to change the colour of the background or circle, this is a good site:
http://www.colorpicker.com/

Step Five: Bluetooth testing:

We are now going to walk through Bluetooth connectivity. While we could just use a library to do all the heavy lifting for us, I decided to explore Bluetooth functionality from scratch. This will hopefully provide greater returns in the long run. Ok, lets create a new Android/Processing Sketch which changes its behaviour depending on whether Bluetooth is enabled or disabled when the sketch is run. We will display a red screen when Bluetooth is switched off, and green when Bluetooth is switched on.

To enable Bluetooth on my Samsung Galaxy SII phone:

Settings >Wireless and Network > Bluetooth Settings > Bluetooth (Turn on Bluetooth) - check the box

To disable Bluetooth on my Samsung Galaxy SII phone:

Settings >Wireless and Network > Bluetooth Settings > Bluetooth - Uncheck the box

In the processing/android IDE, you need to make sure that you update the AndroidManifest.xml file to grant specific permissions. You can either edit the file manually in the sketch folder, however, it is much easier and safer to do the following. In the processing/android IDE, select:

Android > Sketch permissions (as per the picture below)

Make sure that BLUETOOTH and BLUETOOTH_ADMIN are selected (as per the picture below). Then press the OK button.

Then copy and paste the following sketch into the processing/android IDE:

Android/Processing Sketch 2: BluetoothChecker1

/*BluetoothChecker1: Written by ScottC on 17 March 2013
 This will show a red screen if Bluetooth is off, 
 and a green screen when Bluetooth is switched on */

import android.bluetooth.BluetoothAdapter;

BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();
void setup(){
 orientation(LANDSCAPE);
}
void draw(){
 if(bluetooth.isEnabled()){
 background(10,255,30);
 } else {
 background(255,10,30);
 }
}

When you run the BluetoothChecker1 sketch on the device, you will either see a red screen or a green screen depending on whether you had Bluetooth enabled or disabled at the time. Ok, pretty boring, but it is a start. What if we wanted to ask the USER if they would like to enable Bluetooth at the beginning? We could then change the appearance of the screen depending on their selected answer. Before we add this functionality, I would recommend that you read about the following concepts introduced in the next sketch.

startActivityForResult : used to create a new Activity. We create a new Activity to ask the user for permission to enable Bluetooth.
onActivityResult: called when the Activity exits. We use this to find out whether the user granted permission to turn on Bluetooth or not.
BluetoothAdapter.ACTION_REQUEST_ENABLE : This is action we want to take when we launch the activity.
android.content.Intent: Mostly used when launching activities.

While it is actually possible to turn bluetooth on without asking for permission, I thought I would retain my manners for the following sketch:

Android/Processing Sketch 3: BluetoothChecker2

/*BluetoothChecker2: Written by ScottC on 17 March 2013
 
 If Bluetooth is already ON when you run this sketch,
 the background will display BLUE.
 
 If Bluetooth is OFF when you run this sketch but you
 agree to turn it on, the background will display GREEN.
 
 If Bluetooth is OFF when you run this sketch and then
 choose to keep it off, the background will display RED. 
 
 =======================================================*/
 
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
int BACKGND=0; //Set the background to BLUE
//Get the default Bluetooth adapter
BluetoothAdapter bluetooth = BluetoothAdapter.getDefaultAdapter();

/*The startActivityForResult() launches an Activity which is
 used to request the user to turn Bluetooth on. 
 The following onActivityResult() method is called when the 
 Activity exits. */
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){
 if(requestCode==0){
 if(resultCode == RESULT_OK){
 BACKGND=2; //Set the background to GREEN
 } else {
 BACKGND=1; //Set the background to RED
 }
 }
}
void setup(){
 orientation(LANDSCAPE);
 
 /*IF Bluetooth is NOT enabled, 
 then ask user permission to enable it */
 if (!bluetooth.isEnabled()) {
 Intent requestBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
 startActivityForResult(requestBluetooth, 0);
 }
}
void draw(){
 if(BACKGND==0){
 background(10,10,255); //Set background to BLUE
 } else if(BACKGND==1) {
 background(255,10,10); //Set background to RED
 } else {
 background(10,255,10); //Set background to GREEN
 }
}

I tried my best to explain the code via the comments within. I hope it made sense.

Useful Links:

Android Processing Wiki: http://wiki.processing.org/w/Android

Here is a good tutorial which helped me put Processing and Android together:
http://www.creativeapplications.net/android/mobile-app-development-processing-android-tutorial/

And most importantly:
The Android Developers site : Bluetooth

Click here for PART TWO

Click here for PART THREE

Click here for PART FOUR

If you like this page, please do me a favour and show your appreciation :

Visit my ArduinoBasics Google + page.
Follow me on Twitter by looking for ScottC @ArduinoBasics.
Have a look at my videos on my YouTube channel.

However, if you do not have a google profile...
Feel free to share this page with your friends in any way you see fit.

ScottC 17 Mar 17:54

android arduino arduinobasics best arduino blog bluetooth part one processing project setup tutorial

Wireless pinball controller for tablet gaming

This wooden box is a wireless pinball controller and tablet stand. The idea is to set it on a workbench to give you some of the thrill of standing and playing the real thing. [Jeff] has been rather addicted to playing a pinball app on Android lately, and started the journey because he needed a way to give his thumbs some relief.

An Arduino monitors buttons on either side of this wooden controller. [Jeff] is new to working with hardware (he’s a Linux Kernel developer by trade) and was immediately struck with button debouncing issues. Rather than handle this in software (we’ve got a super-messy thread on that issue with our favorite at the bottom) he chose a hardware solution by building an SR latch out of two NAND gates.

With the inputs sorted out he added a BlueSMiRF board to the project which allowed him to connect a Nexus 7 tablet via Bluetooth. At this point he ran into some problems getting the device to respond to his control as if it were an external keyboard. His stop-gap solution was to switch to a Galaxy Tab 10.1 which wasn’t throwing cryptic errors. Hopefully he’ll fix this in the next iteration which will also include adding a plunger to launch the pinball, a part which just arrived in the mail as he was writing up this success.

We’ve embedded his quick demo video after the break.

Filed under: android hacks, arduino hacks

Hack a Day 04 Mar 23:01

android android hacks arduino arduino hacks bluesmirf bluetooth debounce nand pinball

Arduino/Android Wireless Robot

Another Robot, another App(lication) of Arduino. The user [shreks7] built up an Android App for controlling the robot wirelessly and stream live video off an android phone placed on the robot.

The robot has an inbuilt wireless router and two brush-less DC motors and runs on a power source of 26-30V(depends on the requirement) power supply.

The robot streams live video back to the app and can be used for navigation.
Also there is a console for Windows to control the robot and debug it .

It uses Arduino Mega 1280 + Ethernet Shield + Pololu Motor Driver (It is by far the best one i have used) + Belkin Router & Two Android Devices .

There is also a [video] where you can see the robot in action.

Arduino Blog 19 Dec 17:20

android arduino ethernet shield gallery motor driver wireless robot

Mobiton - Robotic Smartphone Shell

Primary image

What does it do?

Uses a smartphone to operate. It can be an assistant, pet, or a telepresence device. Can be anything depends on the mobile app you write.

Hey Guys,

I know, I didn't post for a while. Didn't have time to post some of the projects, sorry about it.

Alright, so here is our new project, we plan to go commercial with it. It is called Mobiton. It is a robotic shell for mobile devices (android currently). You can dock your phone on the device, an application written for the robot pops up and it brings the robot to life.

Cost to build

$150,00

Embedded video

Finished project

Complete

Number

Time to build

Type

URL to more information

Weight

KegDroid makes drinking beer more fun

Are you bored with just drinking beer? Are your friends constantly sneaking into your house and stealing your sacred beverages? If so, perhaps you need KegDroid – the Android controlled beer tap created by [Paul Carff].

Looking for a way to add more excitement to drinking his beer, [Paul] spiced up his tap with a little extra technology. He added an Android tablet for touchscreen navigation of the menus, an Arduino to control the flow sensors and solenoid valves, and an NFC reader to act as security for restricted access. Users must be authenticated before they are allowed to pour any alcohol.

Your name and photo are pulled from your Google+ account as you’re logged in, then you simply select your beverage of choice, and if you’d like a one, eight, or twelve ounce pour. Flow sensors automatically shut off when you have the desired quantity.

Seems like you get more foam than beer, but all in all it’s a cool bar top app.

Check out the video after the break.

Filed under: android hacks, arduino hacks, beer hacks

Hack a Day 08 Nov 22:42

android android hacks arduino arduino hacks beer beer hacks kegdroid

Arduino UNO Rev 3 + Bluetooth Bee + Android

Guys,

behalf of my Awesomeness,

I beg all of you to PLEASE HELP me on my very 1st robot :D

I have an Arduino UNO Rev 3 and a Protyping Sheild

And I need to control 6 DC motors via BLUETOOTH Bee

and my remote control is a App in ANDROID the "BlueBots"

My MAIN concern is

How to combine that 3 products so that I can Control the 6 DC motors

Let's Make Robots 14 Oct 08:08

absolute beginners android arduino bluetooth

Arduino-Controlled Shark Detection System

Justin Hyunh wrote in to share this cool project he and Chris Ladden built: a tweeting anti-shark laser security system! A laser pointer shines on a light sensor. An Arduino detects a low reading from the sensor and uses a BeagleBoard to send a tweet to @BruceSharkAlert and also sends a text message to Justin’s phone.

This may or may not have implications for real-life shark tracking, but I’ll take an excuse to have my shark tweet me when he (or she, I’m no marine biologist) breaches the perimeter over to the sunny side of the tank.

Of course, I’m doing this with my toy shark-on-a-stick and only a laser level and a light sensor, but it’s possible to make this much more accurate and granular just by adding more strategically placed sensors/light sources into the mix.

(In case you didn’t realize, this wasn’t meant to be a REAL shark detection system.)

Filed under: Android, Arduino

MAKE » Arduino 17 Aug 19:00

android arduino

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