Posts with «arduino uno» label

IoT Safe Keeps Latchkey Kids’ Phones on Lockdown

Phones are pretty great. Used as telephones, they can save us from bad situations and let us communicate while roaming freely, for the most part. Used as computers, they often become time-sucking black holes that can twist our sense of self and reality. Assuming they pick up when you call, phones are arguably a good thing for kids to have, especially since you can hardly find a payphone these days. But how do you teach kids to use them responsibly, so they can still become functioning adults and move out someday? [Jaychouu] believes the answer is inside of a specialized lockbox.

This slick-looking box has a solenoid lock inside that can be unlocked via a keypad, or remotely via the OBLOQ IoT module. [Jaychouu] added a few features that drive it out of Arduino lockbox territory. To prevent latchkey children from cheating the system and putting rocks (or nothing at all) in the box, there’s a digital weight sensor and an ultrasonic sensor that validate the credentials of the contents and compare them with known values.

Want a basic lockbox to keep your phone out of reach while you work? Here’s one with a countdown timer.

Superbly Synchronized Servos Swaying Softly

LEDs and blinky projects are great, and will likely never fade from our favor. But would you look at this sweeping beauty? This mesmerizing display is made from 36 micro servos with partial Popsicle sticks pasted on the arms. After seeing a huge display with 450 servos at an art museum, [Doug Domke] was inspired to make a scaled-down version.

What [Doug] didn’t scale down is the delightful visuals that simple servo motion can produce. The code produces a three-minute looping show that gets progressively more awesome, and you can stare at that after the break. Behind the pegboard, a single, hardworking Arduino Uno controls three 16-channel PWM controllers that sweep the servos. We like to imagine things other than Popsicle sticks swirling around, like little paper pinwheels, or maybe optical illusion wheels for people with strong stomachs.

You won’t see these in the video, but there are five ultrasonic sensors mounted face-up on the back of the pegboard. [Doug] has optional code built in to allow the servo sticks to follow hand movement. We hope he’ll upload a demo of that feature soon.

Servos can be hypnotic as well as helpful, as we saw in this 114-servo word clock.

Via Arduino blog

Air Hockey Table is a Breeze to Build

Many of us have considered buying an air hockey table, but are put off by the price. And even if the money is there, those things take up a lot of space. How often are you really going to use it?

This DIY air hockey table is the answer. It’s big enough to be fun, but small and light enough to easily stow away in the off-season. At ~$50, it’s a cheap build, provided you have a vacuum cleaner that can switch to blower mode. The strikers, goals, corner guards, and scoreboard enclosure are all 3D-printed, while the pucks and playfield are laser-cut acrylic. [Technovation] glued acrylic feet to the strikers to help them last longer.

The scoreboard is an Arduino Uno plus an LCD that changes color to match the current winner. Scoring must be entered manually with button presses, but we think it would be fairly easy to detect a puck in the goal with a force or weight sensor or something. For now, the RGB LEDs around the edge are controlled separately with a remote. The ultimate goal is to make the Arduino do it. Shoot past the break and cross-check it out.

Already have a table? Had it so long, no one will play you anymore? Build yourself a robotic opponent.

sprintf function

Description

This tutorial will help you to understand the sprintf function, and how to use it. Essentially, the sprintf function allows you to construct a string using a pre-formatted string template to which you can insert variables at pre-defined locations. The sprintf function will "compile" the string and assign it to a char array. All you have to do is make sure that the char array is large enough to hold all of the characters in the string. The best way to understand the sprintf function is with examples. And luckily, I have examples. What are we waiting for ? Let's dive in.

Parts Required: an Arduino and a USB cable.

 
 

sprintf ( char* array,   const char* strTemplate,   var1...);

 
 

Arduino IDE

While there are many Arduino IDE alternatives out there, I would recommend that you use the official Arduino IDE for this project. I used the official Arduino IDE app (v1.8.5) for Windows 10.
Make sure to get the most up-to-date version for your operating system here.


 
 

Arduino Code

The code below will show you how to use the sprintf function and includes a number of different format specifiers to play with. In each case the sprintf function writes to the "data" character array, and subsequently sends it through to the Serial monitor. The string template helps to construct the data output, allowing you to insert variables at specific locations within the text. The format of the variable is defined by the "format specifier" used in the sprintf function. The format specifier is always prefixed with a percentage sign (%).

 
 

Serial Monitor Output

  1. Upload the code to the Arduino.
  2. Open the Serial monitor in the Arduino IDE (Ctrl+Shift+M).
  3. Ensure that you have set the baud rate in the Serial monitor to 9600.
  4. You should see the following output:

 

The sprintf function requires that you have a character array to store the output. In the example code above, the output is stored in the "data" character array. It also requires a template that tells the function where to insert the variables. As you can see from the table below, the variables will be formatted based on the format specifier used. The format specifier can be quite useful for numeric conversions. Eg. decimal to hex conversions.

 
 

Format Specifiers

Some of the different format specifiers that can be used with the sprinf function are listed below.

Conclusion

Now that you know all about the sprintf function, I hope it will inspire you to use it in your own projects. Please let me know in the comments below how you use the sprintf function, and whether there was anything that you feel I failed to mention in this tutorial.
Happy Coding !!

 
 

If you found this tutorial helpful, please consider supporting me by buying me a virtual coffee/beer.

$3.00 AUD only
 

Social Media

You can find me on various social networks:

Follow me on Twitter: ScottC @ArduinoBasics.
I can also be found on Instagram, Pinterest, and YouTube.
And if all else fails, I have a server on Discord.


Universal Remote a Grove Infrared project


 
 

Description

This project will convert an ordinary Keyes infra-red (IR) remote
into a programmable universal remote.

 
A single button press on the Keyes remote will be converted into precise Sony IR signal combinations using an Arduino UNO and an assortment of Seeedstudio Grove modules.
You can assign signal combinations from more than one remote if desired.
An example combination could be to:
  • Turn on the TV and then switch channels.
  • Turn on the TV, sound system, and air-conditioner.
  • Turn up the volume x 3.
With only one button press of the Keyes remote, the entire cascade of Sony signals ensues. This project can be customised for other IR methodologies, however, you may have to modify the Arduino code to accommodate them.

 
 

Parts Required

  1. Arduino Uno (or compatible board)
  2. Grove Base Shield (v2)
  3. Grove Infrared Receiver
  4. Grove Infrared Emitter
  5. Grove Button
  6. Grove 16x2 LCD (White on Blue)
  7. Grove Universal 4 pin buckled cable: one supplied with each module.
  8. KEYES IR Remote Control
  9. SONY IR remote control
  10. USB cable - to power and program the Arduino
  11. Battery pack / Power bank

 
 

More information about the Grove modules can be found here:

**Please Note: The Grove Base shield has 14 pins on the Analog side, and 18 pins on the digital side. Check the number of pins on your Arduino UNO (or compatible board) to ensure the shield will sit nicely on top. NOT compatible with Arduino boards that have the Arduino Duemilanove pin header layout.

 
 

Arduino IDE

While there are many Arduino IDE alternatives out there, I would recommend that you use the official Arduino IDE for this project. I used the official Arduino IDE app (v1.8.5) for Windows 10.
Make sure to get the most up-to-date version for your operating system here.


 
 

Libraries required

The following libraries will be used in the Arduino code:

  1. Wire Library
  2. IRLib2 Library
  3. rgb_lcd Library

Wire Library

The Wire library is used for I2C communication for the Grove LCD screen and is built into the Arduino IDE - no additional download required for this library.
 

IRLib2 Library

The IRLib2 Library is actually a "set" of IR libraries, which can be downloaded from GitHub - here. In this project, I will be transmitting and receiving NEC and Sony IR remote signals.
The required libraries (within the set) will be:
  • IRLibRecv.h
  • IRLibDecodeBase.h
  • IRLibSendBase.h
  • IRLib_P01_NEC.h
  • IRLib_P02_Sony.h
  • IRLibCombo.h
Please see the IRLib2 GitHub Page for installation instructions.
 

rgb_lcd Library

The rgb_lcd.h library simplifies the operation of the LCD screen.
Download the rgb_lcd.h library from GitHub. Install the rgb_lcd.h library ZIP file into the Arduino IDE:
  1. Load the Arduino IDE
  2. Navigate to Sketch >Include library > Add .ZIP library...
  3. Select the downloaded zip file from GitHub, and press the "Open" button
  4. Check that it installed correctly by navigating to File > Examples > Grove-LCD RGB Backlight

 
 
 
 

Arduino Code

It is always best to upload the Arduino code to the board before you make any of the connections. This way you prevent the Arduino from sending current to a component accidentally. The code is available on my GitHub repository. Or you can have a look below. This code was written for an Arduino UNO, and may need to be modified if you are using a different board.

 
 
 
 

Connection instructions

If you are using the Grove Base Shield (v2). The connections are extremely simple. Use the following table as a guide. Please note that the code above assumes the following connections.
 

 

As per the table above, you would use a Grove universal 4-pin buckled cable and connect one side to D2 on the Grove base shield, and the other side would connect to the Grove Infrared Emitter.
D3 on the base shield would connect to the Grove Infrared Receiver, and so on.
You can connect the 16x2 LCD module to ANY of the four I2C connectors on the Grove base shield.

If you do not have a Grove Base shield, you have the option to use female-to-male jumper wires (together with a breadboard). But it is easier just to get the base shield and use the universal connectors.

 
 
 
 
 
 

Project Explained

When you apply power to the Arduino, the first thing that appears on the LCD screen is:
 


 
After pressing the Grove button (connected to D5), it displays the following message:
 

 
This is the cue to press and send a signal from the Keyes remote to the Infrared receiver (which is connected to D2). The Arduino will decode the Keyes remote signal, store the value in an array, and display the signal briefly on the LCD. The LCD should now show a message:
 

 
This message is a cue to press and send the FIRST signal from the Sony remote to the Infrared receiver. The Arduino will decode and store the Sony remote signal in a different array, and display it briefly on the LCD. You have the option to send a maximum of THREE Sony signal combinations to the Infrared receiver at this step in the process. The minimum number of Sony signals you can send is zero. The way to tell the Arduino that you do not want to send any further Sony signals to the receiver in this step, is by pressing the Grove Button (connected to D5).
 
The Arduino is programmed to receive a total of 5 Keyes signals, and each signal can be paired with a maximum of 3 Sony signal combinations. Once you have recorded all of the signal combinations, you will get a message:
 

 
The Arduino will now enter the final "Universal remote mode". In this mode, it will listen out for ANY of the 5 Keyes IR remote signals recorded previously, and will send the associated Sony signal combination in return. For example, if you press the number 1 on the Keyes remote, you could potentially have it so that the Arduino will transmit a Sony signal combination to turn on the TV and jump to a specific channnel.
 
The LCD will display each of the signals being transmitted. You will know you are in "Universal remote" mode because the LCD will display:
 

 
While you may be tempted to throw your Sony remote away at this stage (because you no longer have a use for it)... I would hold on to it just in case. The signals are not stored permanently. They disappear when the Arduino is powered off. But it doesn't have to be that way. You can easily modify the code to store it in eeprom memory or something.
 
That is not the only thing you can change.Technically, you could record the signal for any remote, however, you may need to include additional libraries or code to accommodate the alternate remote symbology. You can also modify the text messages on the LCD screen to make more sense to you. The LCD can only display 16 characters per row. So keep that it mind, when you come up with creative captions.
 
I would also like to mention the reason I chose not to use Seeedstudio's IR library, was because it took up too much memory. Their library probably accommodates for a wide range of symbologies. I chose the IRLib2 Library because I could select only the symbologies that I used (Sony and NEC). Thereby reducing the total amount of memory necessary to run the project. In fact, I have been finding that many of Seeedstudio's libraries to be very memory hungry. I originally wanted to create a gesture controlled remote. But the library combinations eliminated that possibility due to the cumulative memory requirements.
 
 
 
 

Conclusion

The IRLib2 library is the key to the success of this project. Without that library, this project would have been ten times harder. I was quite amazed by the effectiveness of this record / playback technique. It felt very weird to be operating my SONY TV with a cheap and nasty Keyes remote. It was quite surreal. While I chose to control my TV in this way, I could have just as easily recorded signals from one of my other remotes that use infrared signals. As more and more devices become controllable by remotes, the more I will consider turning this project into a permanent fixture in my house. A gesture controlled remote would have been nice, however, it looks like I will have to find some other use for that module now.

If you found this tutorial helpful, please consider supporting me by buying me a virtual coffee/beer.

$3.00 AUD only
 

Social Media

You can find me on various social networks:

Follow me on Twitter: ScottC @ArduinoBasics.
I can also be found on Instagram, Pinterest, and YouTube.
And if all else fails, I have a server on Discord.



             

Driving a Controllerless LCD With the Humble Arduino Uno

These days, you could be forgiven for thinking driving an LCD from a microcontroller is easy. Cheap displays have proliferated, ready to go on breakout boards with controllers already baked in. Load up the right libraries and you’re up and running in a matter of minutes. However, turn your attention to trying to drive a random LCD you’ve yanked out of a piece of old equipment, and suddenly things get harder. [Ivan Kostoski] was in just such a position and decided to get down to work.

[Ivan]’s LCD was a 320×240 STN device salvaged from an old tape library. The display featured no onboard controller, and the original driver wasn’t easily repurposed. Instead, [Ivan] decided to drive it directly from an Arduino Uno.

This is easier said than done. There are stringent timing requirements that push the limits of the 8-bit platform, let alone the need for a negative voltage to drive the screen and further hardware to drive the backlight. These are all tackled in turn, with [Ivan] sharing his tips to get the most flexibility out of the display. Graphics and text modes are discussed, along with optimizations that could be possible through the varied use of available RAM and flash.

The code is available on Github. If you need inspiration for your own controllerless LCD driver. [Ben Heck] has done similar work too, using FPGA grunt to get the job done.

ESP-13 WiFi Shield Web Server

Description

This tutorial will show you how to setup a simple webserver on your ESP-13 WiFi Shield and display a table of all of the WiFi Access Points within it's range (and refreshed every 5 seconds).
The ESP-13 shield will create it's own WiFi access point, which means that you can take this project anywhere you want to. You do not have to be connected to your home/work WiFi network to see the webpage. The limitation however, is that your device must be within WiFi range of the ESP-13 WiFi shield in order to see the results of the WiFi scan.

Let me show you how to put this project together:
COMING SOON....

ScottC 16 Sep 18:13

Getting Started with the Keyes ESP-13 WiFi Shield

Description

This tutorial will help you get started with the KEYES ESP-13 WiFi Shield.

The ESP-13 WiFi Shield is compatible with an Arduino UNO and has the same form-factor. Essentially this shield will give your Arduino project WiFi capabilities. While it interfaces nicely with the Arduino, it can operate without it. However, if I were planning on using the shield independantly, then I probably would opt for an ESP module rather than a shield.

I bought my shield from Jaycar (CAT.NO: XC4614), however you can get it much cheaper from other online retailers at about a quarter of the price. The instructions on the Jaycar website are not that good, and at first I thought I had bought myself a useless product. It just didn't seem to work regardless of what I tried. There were some tutorials online that gave me hope, only to find that my shield was not quite the same and therefore I did not get the same results. But after countless hours of trial and error and patching various bits of knowledge together, I finally worked out how to use this shield. Everything has fallen into place. And it is easier that you would think... let me show you how.

Parts Required

  1. Arduino UNO (or compatible board)
  2. KEYES ESP-13 WiFi Shield - from Jaycar (Cat. No: XC4614)
  3. USB cable - to connect Arduino to Computer
  4. 4 wires: 4 x Male to Male connectors


Libraries and IDE

Arduino IDE

While there are many Arduino IDE alternatives out there, I would recommend that you use the official Arduino IDE for this project. I used the official Arduino IDE app (v1.8.5) for Windows 10.
Make sure to get the most up-to-date version for your operating system here.


Upload BareMinimum Sketch

Upload a BareMinimum Sketch to the Arduino UNO (or compatible board) before making any connections to the ESP-13. We want to upload the BareMinimum sketch because we don't want the Arduino UNO interfering with our setup in anyway. Here is how to do that:

  1. Start your Arduino IDE
  2. Connect the Arduino UNO to the Computer using a USB cable
  3. Select: File > New (or Ctrl + N)
  4. Select: File > Examples > 01.Basics > BareMinimum
  5. Select: Tools > Board > Arduino/Genuino UNO
  6. Select: Tools > Port > COM4 (Your Arduino may be on a different COM port)
  7. Select: Sketch > Upload (or Ctrl + U) - or click on right arrow symbol
  8. After the sketch has uploded. Disconnect the USB cable from the computer/Arduino.



IDE Configuration for ESP-13

Now for the fun part. The ESP-13 WiFi Shield is itself a microcontroller, however, the Arduino IDE is not by default, configured to communicate with or program the ESP-13 WiFi Shield. We are about to change that:

  1. Select File > Preferences from the Arduino IDE menu (or Ctrl+Comma)
  2. Insert the following text into the Additional Boards Manager URLs field:
    If there is a URL in that space already, then insert a comma, and append the URL to the end:

    http://arduino.esp8266.com/stable/package_esp8266com_index.json


  3. Once the URL is added, press OK.
    This will allow us to install the ESP8266 package in the next step.


Installing the ESP8266 board

  1. Select: Tools > Board: "xxxx" > Boards Manager
  2. Search for ESP8266 using the Search bar
  3. Select the "esp8266 by ESP8266 Community" board from the list.
  4. Select the latest or most up-to-date version from the drop-down box (eg. 2.4.2)
  5. Press the Install button.
  6. Make sure that the esp8266 board is installed. Then press the "Close" button
  7. Choose the ESPDuino(ESP-13 Module) from the ESP8266 Modules list:
    Tools > Board: "xxxx" > ESPDuino(ESP-13 Module)






ESP-13 Flash Settings

You will then want to check that you have the following settings in the Tools menu of the Arduino IDE:

  • Board: "ESPDuino (ESP-13 Module)"
  • Flash Size: "4M (1M SPIFFS)"
  • Debug port: "Disabled"
  • Debug Level: "None"
  • IwIP Variant: "v2 Lower Memory"
  • Reset Method: "ESPduino-V2"
  • VTables: "Flash"
  • CPU Frequency: "80MHz"
  • Upload Speed: "115200"
  • Erase Flash: Only Sketch
  • Port: - (we will select that later)

The Arduino IDE is now able to communicate with, and program the ESP-13 WiFi shield.
Now let us have a look at how to use the default AI-Thinker AT-firmware that comes pre-loaded on the shield.


Preparing the WiFi Shield for Communication

The Keyes ESP-13 WiFi shield comes pre-loaded with AI-Thinker firmware. I thought I just had to place the WiFi shield on top of the Arduino UNO, and I should be able to send through some AT commands via the Serial monitor. Yes - it is a shield, and yes, we will use it as a shield later on, but if you want to use the Serial monitor while the shield is sitting on-top of the Arduino UNO, you will need to make use of the SoftwareSerial library. You can go down this path, but it is cumbersome. There is a better way. We will still need the Arduino UNO, but we need to connect it to the ESP-13 Shield in the following manner:

Wire Connections

  1. Make sure that the Arduino UNO is OFF (i.e. not connected to power or USB port)
  2. Place the ESP-13 WiFi shield NEXT TO the Arduino UNO
  3. Connect a Red wire between 5V on Arduino UNO, and 5V (Arduino side) of the ESP-13 shield
  4. Connect a Black wire between GND on Arduino, and G (Arduino side) of the ESP-13 shield
  5. Connect a Green wire between D0(RX) on Arduino, and TX (UART - Arduino side) of ESP-13
  6. Connect a Yellow wire between D1(TX) on Arduino, and RX (UART - Arduino side) of ESP-13
  7. Make sure that both of the switches on the ESP-13 WiFi Shield are in the "ON" position.

Serial Monitor Setup

  1. Plug the USB cable into the computer, and the other end into the Arduino
  2. You should see a Red LED ignite on the ESP-13 Shield.
  3. In your Arduino IDE, make sure the correct COM port is selected:
    Tools > Port > COM4 (Arduino/Genuino UNO) - your port may be different.
  4. The IDE recognises that an Arduino is using that COM port, even though ESP-13 Board selected
  5. Open the Serial Monitor: Tools > Serial Monitor (or Ctrl + Shift + M)
  6. Select: Both NL & CR from the drop-down box at the bottom right side of the Serial Monitor.
  7. Select: 115200 baud from the other drop-down box in the Serial Monitor window.
  8. Press the RESET (RST) button on the bottom left of the ESP-13 WiFi Shield.
  9. You may see some garbled information come through, but you should see "Ai-Thinker Technology Co.,Ltd" and "ready" messages in the debug window.
  10. You can now send through your AT-commands to the ESP-13 WiFi shield.


Using default AI-Thinker AT-firmware

Now is a good time to test the AI-Thinker AT-firmware. It is possible to program the Arduino to send a sequence of AT commands to the ESP-13 WiFi Shield, but for demonstration purposes, I will show you how to send the commands manually via the Serial monitor.

  1. If you see "ready" within the Serial Monitor window, the ESP-13 is ready to receive AT commands.
  2. Type: AT into the box at the top and press the Send button (or Enter)
  3. You should now see the AT command in the debug window, and a response "OK"

If you received the OK message, then your communication with the ESP-13 was successful.
A good list of AT commands and explanations can be found here.
Another list of AT commands can be found here.

The commands allow you to test, query and configure the ESP-13 shield. Essentially a command-line interface. Try out the following commands to get a feel for these functions/queries. The commands are in bold, and I placed some of the responses that I got in the line below.

  1. AT
    Response: OK

  2. AT+RST
    This resets the ESP-13 board. It provides some info about the board.

  3. AT+GMR
    AT version: 0.40.0.0 (Aug 8 2015)
    SDK version: 1.3.0
    Ai-Thinker Technology Co.,Ltd.
    Build:1.3.0.2 Sep 11 2015

  4. AT+CIFSR
    +CIFSR:APIP, "192.168.4.1"

  5. AT+CWMODE?
    +CWMODE:2 [1=STA, 2=AP, 3=BOTH]

  6. AT+CWLAP
    ERROR

  7. AT+CWMODE=3

  8. AT+CWLAP
    +CWLAP:(3,"MYACCESSPOINT", -53, "xx:xx:xx:xx:xx:xx",6,-12)

So there you go. Now you have everything need to configure your ESP-13 WiFi shield. Once you are tired of playing around with AT commands, I will show you how to re-program and upload sketches to the ESP-13 WiFi Shield, and use it the way it was designed to be used (i.e. as a shield). To upload sketches to the Shield, you will need one extra wire. But I think that deserves to be another tutorial. Stay tuned.

Summary

In this tutorial, I showed you how to configure your Arduino IDE for the ESP-13 shield. I also explained how to wire the ESP-13 WiFi shield so that you can communicate with it using the Serial monitor. I hope this tutorial helped you in some way. If it did, please let me know in the comments below. I will be following up with another tutorial, which will show you how to upload sketches to the ESP-13 WiFi Shield, and free it from your computer.


 
 

Social Media

You can find me on various social networks:


Visit my ArduinoBasics Google + page.
Follow me on Twitter by looking for ScottC @ArduinoBasics.
I can also be found on Pinterest and Instagram.
Have a look at my videos on my YouTube channel.

             

Getting Started with the Keyes ESP-13 WiFi Shield

Description

This tutorial will help you get started with the KEYES ESP-13 WiFi Shield.
The ESP-13 WiFi Shield is compatible with an Arduino UNO and has the same form-factor. Essentially this shield will give your Arduino project WiFi capabilities. While it interfaces nicely with the Arduino, it can operate without it. However, if I were planning on using the shield independantly, then I probably would opt for an ESP module rather than a shield.
I bought my shield from Jaycar (CAT.NO: XC4614), however you can get it much cheaper from other online retailers at about a quarter of the price. The instructions on the Jaycar website are not that good, and at first I thought I had bought myself a useless product. It just didn't seem to work regardless of what I tried. There were some tutorials online that gave me hope, only to find that my shield was not quite the same and therefore I did not get the same results. But after countless hours of trial and error and patching various bits of knowledge together, I finally worked out how to use this shield. Everything has fallen into place. And it is easier that you would think... let me show you how.


Coming soon......................

Feed Barbie with the J’ai faim! mechatronic game

According to this project’s write-up, while some struggle to get enough nourishment, those in more developed countries often aspire to consume too little food. As an apparent commentary on this situation, Niklas Roy and Kati Hyyppä have created a mechatronic game called J’ai faim!, French for “I’m hungry!”

In this Arduino-controlled game, participants rotate a Barbie head to point her comically over-sized tongue over a piece of sushi lit up by an LED. When in position, the player fires her solenoid-actuated tongue using the joystick, and if the correct sushi is eaten the score progresses from “starving” to “well fed.” 

You can see the game—reminiscent of a very strange version of whack-a-mole—in the video below.