Posts with «hc-05» label

This 3D-Printed Robotic Vacuum Sucks

After you’ve taken a moment to ponder the turn of phrase used in the title, take a look at this scratch-built robotic vacuum created by [theking3737]. The entire body of the vacuum was 3D printed, and all of the internal electronics are off-the-shelf modular components. We can’t say how well it stacks up against the commercial equivalents from iRobot and the like, but it doesn’t look like it would be too hard to build one yourself to find out.

The body of this rather concerned-looking robot was printed on a DMS DP5 printer, which is a neat trick as it only has a build platform of 200 mm x 200 mm. Once all the pieces were printed, a 3D pen was used to “weld” the sections together. The final result looks a bit rough, but should give a bond that’s just as strong as the printed parts themselves.

The robot has four sets of ultrasonic range finders to detect walls and obstacles, though probably not in the positions you would expect. The right side of the robot has two sets of sensors, while the left side only gets one. We aren’t sure the reasoning behind the asymmetrical layout, but presumably the machine prefers making right turns.

Control is provided by an Arduino Mega and the ever-reliable HC-05 Bluetooth module. A companion Android application was written which allows configuring the robot without having to plug into the Arduino every time you want to tweak a setting.

We can’t say we’ve seen that many DIY robotic vacuums here at Hackaday, but we’ve certainly featured our fair share of hacks for the commercially available models.

Convert Any USB Keyboard to Bluetooth

[DastardlyLabs] saw a video about converting a PS/2 keyboard to Bluetooth and realized he didn’t have any PS/2 keyboards anymore. So he pulled the same trick with a USB keyboard. Along the way, he made three videos explaining how it all works.

The project uses a stock DuinoFun USB mini host shield with a modification to allow it to work on 5V. An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, shield–to connect it to the Arduino.

The result is a nice little sandwich with a USB plug, a Bluetooth antenna, and some pins for reprogramming if necessary. Resist the urge to solder the Bluetooth board in–since it talks on the same port as the Arduino uses for programming, you’ll have to remove it before uploading new code.

If you need help reprogramming the HC-05 Bluetooth module, we’ve covered that before. This project drew inspiration from [Evan’s] similar project for PS/2 keyboards.

Filed under: Arduino Hacks
Hack a Day 04 Sep 18:01

How to enter AT mode in HC-05 bluetooth module

Using HC-05 in AT mode

Hello guys, In this post we will cover how to change password, name or mode (master or slave) in HC-05 module. 

Things required:

1. Arduino Uno board
2. Jumper wires
3. HC-05
4. Little bit patience :p

Note: Use can USB-TTL instead of arduino uno board. In this case, arduino uno board is simply used as USB-TTL converter.

Steps to follow:

First of all, upload a blank program to arduino.

/* Arduino Program */

void  setup(){


void  loop(){


Connections should be a follows:

Arduino                              HC-05
TX              ====>             TX
RX              ====>             RX
VCC            ====>             VCC
GND           ====>              GND

Note: Before powering up the arduino, the button should be pressed and it should be released after some time after powering up the arduino.  

If there is no switch on your module,  you have to apply 3.3 volt to pin number 34 of HC-05 before power up. After power remove the 3.3 volt.

Now, if the HC-05 in at mode led will blink after every 2 seconds.

After connection, open serial monitor. The baud rate should be selected to 38400 and both nl and cr should be selected.

After this, you have to pass AT commands:

AT and press enter
The response is OK

AT+ROLE? and press enter
The response is 0 or 1
0- Slave
1- Master

AT+UART? and press enter
The response is Baud rate

AT+PSWD? and press enter
The response is 1234    // it's your password.

For changing the password, command is AT+PSWD=1587  
This commannd will set the password to 1587.

Check out the video:

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Stay tuned for more updates.

OK Google, Open Sesame

There are a myriad of modern ways to lock and unlock doors. Keypads, Fingerprint scanners, smart card readers, to name just a few. Quite often, adding any of these methods to an old door may require replacing the existing locking mechanism. Donning his Bollé sunglasses allowed [Dheera] to come up with a slightly novel idea to unlock doors without having to change his door latch. Using simple, off the shelf hardware, a Smartwatch, some code crunching and a Google Now app, he was able to yell “OK Google, Open Sesame” at his Android Wear smartwatch to get his apartment  door to open up.

The hardware, in his own words, is trivial. An Arduino, an HC-05 bluetooth module and a servo. The servo is attached to his door latch using simple hardware that looks sourced from the closest hardware store. The code is split in to two parts. The HC-05 listens for a trigger signal, and informs the Arduino over serial. The Arduino in turn activates the servo to open the door. The other part is the Google Now app. Do note that the code, as he clearly points out, is “barebones”. If you really want to implement this technique, it would be wise to add in authentication to prevent all and sundry from opening up your apartment door and stealing your precious funky Sunglasses. Watch a video of how he put it all together after the break. And if you’re interested, here are a few other door lock hacks we’ve featured in the past.

Filed under: Android Hacks, hardware

New Project: DIY Arduino Bluetooth Programming Shield

Upload sketches to your Arduino wirelessly with a DIY Arduino Bluetooth Programming Shield.

Read more on MAKE

Processing communicating with Arduino via Bluetooth problems

I am at my wits end! Ive spent the last three or so hours trying to get this to work with no avail.

read more

Let's Make Robots 05 Feb 09:29
arduino  avr  bluetooth  com  hc-05  processing  serial