Introduction: BT-Box

This is just just a prototype.

With this device you can control your music wirelessly over bluetooth.

Here is my video:

Step 1: Things You Need...

• Soldering Tools

• 3d printer (not a must)

• Arduino (Nano / Mini / pro Mini...)

• RN-42 / EZ-KEY HID / HC-05 flashed with RN-42 firmware (visit:

• Pin Headers (male and female)


• Encoder

• Wires

• Li-Ion battery

Step 2: Soldering... ;(

This is the ennoying part of this project.

You can see the diagram below.

I used thin non-isolated copper wire for the connections.

I also recommend using a small slide switch to turn the device on / off.

I printed a little case for my 18650 Li-Ion battery. I will put the .stl-files below.

i have also 3d printed knob for the Encoder (.stl-file below...)

Here you can see how I made it...

Step 3: Code

Here is the code: just upload it to your arduino board.

You have to put your RN-42 module into keyboard-mode AND baud rate of 9600

Step 4: Enclosure

This project is not finished yet.

So I do NOT have a case yet. ;(

But you can make your own.

I'm using Tinkercad for 3D design because Tinkercad is super easy for beginners. And it's FREE.

You can also add some buttons or LED's.

Step 5: Testing

Now the best part: TESTING!!!

Now grab your tablet / mobile (or what ever) enter your bluetooth settings. When you turn the BT-Box on, a bluetooth keyboard, tagged with your previously chosen name, should appear. Connect to it!

Now when you turn the Encoder, the volume should increase or decrease. When you push it it should stop your music.

And that's it!

I hope you enjoyed it!