I want to make a device which will send a data to a mobile phone which is connected using Bluetooth.

Here is the thing: http://www.youtube.com/watch?v=g0qARDGJj1w.

I want something like this. The problem is I have no electrical background. But I have theoretical knowledge as I had a few electrical subjects in college.

The problem is: I don't understand what should I Google, precisely. Just throw me in the best direction so I don't get lost and don't waste time. Give me a basic idea or something that will motivate me.

I don't want the exact thing shown in video. I just want following thing to happen at least:

The user pushes a button, read what that button is for (say it is for the letter 'A'), then the mobile phone will show the letter 'A' in some app, e.g. notes.

Here I am considering data could be sent over Bluetooth, and the mobile phone is an Android device.

  • \$\begingroup\$ i have question.i have an arduino connected to a bluetooth module.to this bluetooth module i can communicate via a pc.but instead of that i need a button to be pressed and the data (may be 1) should be recieved by the arduino with the help of the bluetooth module.the button needs to be bluetooth enbled.how can i solve the problem about this button thing?? \$\endgroup\$
    – user19265
    Commented Feb 21, 2013 at 9:43
  • \$\begingroup\$ @ASHISHKABRAHAM you shouldn't post your own question as an answer. If you think you have a valid question, you can create a new one, but please take make it clear and check the spelling and formatting. \$\endgroup\$
    – clabacchio
    Commented Feb 21, 2013 at 15:56
  • \$\begingroup\$ Teardown a Bluetooth keyboard, connect wires to the A key, pair the keyboard with your smartphone and short out the wires. \$\endgroup\$
    – KalleMP
    Commented May 26, 2018 at 9:40

2 Answers 2


This easiest way to do this is to buy a bluetooth module which has serial port profile built-in to its firmware (Roving networks/ panasonic etc have such modules). Assuming your "device" has a microcontroller, the microcontroller could communicate to the BT module via some communication interface (say UART) to transmit and receive data. At the mobile phone end, you need to write an App which will connect and pair with the BT module in your device and once it establishes a stream, your App can transmit and receive data with your device.

This is quite straightforward, I was able to do this and transfer files from my device to an android phone in a week of tinkering.

  • \$\begingroup\$ Oh..I read some articles on UART and few others it's really like storm on me.... \$\endgroup\$
    – Mubeen Shk
    Commented Aug 2, 2012 at 12:47
  • 1
    \$\begingroup\$ @MubeenShk our site is different from other forums, please take the time to explain exactly what you are doing and where you are stuck and users will answer with how to go about that specific technical problem. We are not here to get contracted out, well, maybe some are here for their resumes for contracts, but answering the question here is our goal. Asking about UART is really another question. \$\endgroup\$
    – Kortuk
    Commented Aug 2, 2012 at 15:05
  • \$\begingroup\$ @kortuk : correct..ok. \$\endgroup\$
    – Mubeen Shk
    Commented Aug 2, 2012 at 15:28
  • \$\begingroup\$ If you are a complete newbie, then you need to learn about microcontrollers, some C programming, read and understand the data sheet of the module you plan to use etc.. It will take some time. Or you could just outsource the project to someone else (hint hint :D). \$\endgroup\$
    – govind m
    Commented Aug 3, 2012 at 3:09

Try the JY-MCU Bluetooth Module (sorry, couldn't find a datasheet). It has gained quite a bit of popularity amongst the microcontroller community, particularly because it is extremely easy to interface. It uses a serial/RS232 UART, so it is very easy to implement (just need the four SPI pins: GND, VCC, TX, RX).

This Instructable is very well written, and is exactly what you are looking for. The module is used with an Arduino, paired with an Android phone. Control an Arduino from your Android device using a cheap bluetooth module. Control an Arduino from your Android device using a cheap bluetooth module.

I just received this from eBay, and I paid $7.00. I will also be doing something similar to what you are doing.

  • \$\begingroup\$ Hey i'm a complete newbie..So my question is.. I followed what above link says..suppose I'm done with that but if I want to print letter 'A' on my android device how do I do that. If I plug a push button on the white board and pressed it how it will recognize it and display 'A' on the android screen \$\endgroup\$
    – Mubeen Shk
    Commented Aug 2, 2012 at 12:36
  • \$\begingroup\$ You would just do Serial.println("A"); in response to the button press (just one more line of code to detect if the button was pushed) by using an if statement. I will eventually do something similar, and I'll e-mail you once I am done - sorry, I don't use Facebook. \$\endgroup\$
    – capcom
    Commented Aug 2, 2012 at 13:18
  • \$\begingroup\$ @MubeenShk Keep the questions on site, there is a chat room if you need it to back and forth discuss, but answers here reward our friend capcom with reputation, rights and more importantly help more people then just one. Answers explained here will help the broad community and be the result on google instead of explaining what to google. \$\endgroup\$
    – Kortuk
    Commented Aug 2, 2012 at 14:57

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