Introduction: Bluetooth48G - Upcycle Broken Hp48G Keyboard

A guided upcycle project for a broken hp48.

Reuse the keyboard and make it work as a bluetooth keyboard for your phone or/and PC.

It works great with EMU48 on Android phones and on Windows.

See it working on a demo video (youtube):

Step 1: Opening the Hp48 - Testing the Hp48 Keyboard

Please check out my priour project:


The keyboard is very sensitive, even with low currency (to not damage the key pressing mechanism).

Step 2: Bluetooth Modul

I used for this project:

* Adafruit Feather nRF52 Bluefruit AF3406.

* compatible battery (see Adafruit Manual)

* a lot of wires - better you have different colors

Step 3: Program Code (Arduino)

Code was creaded and uploaded with Arduino IDE over USB.

Your need to pair the keyboard with your computer/mobile phone.

No additional driver is needed.

Step 4: Soldering the Wires.

Additional 1MOhn resistors are used to prevent signal noise.

Connecting my keyboard was very tricky: I used bended springs of pens for the connectors - maybe you have a better idea.

Have a nice time building your own keyboard.

Step 5: Pictures of the Project