I saw a gif of this keyboard a couple of weeks ago on Reddit so decided to buy one and modify it to work on my PC instead of the pocket PC it was designed for. So here is the first tutorial of someone doing this with this keyboard (according to 2 days of searching the internet for people that have done it).
Step 1: Collect Components
- 1x MAX232
- 4x 1uF Capacitors
- 1x Arduino Pro Micro
- 4x 12mm M2.5 nuts & bolts
- 1x Top (3d printed from STL file)
- 1x Bottom(3d printed from STL file)
And last but not least the HP Compaq IPAQ G750 Keyboard
Step 2: Take Keyboard Apart
First, remove the screws on the top and bottom as shown in the first 2 images. Then the top panel should be able to be removed to expose the internal circuit and disconnect the top connector.
Then remove the 2 screws on the underside of the connector to allow you to remove the circuit board with the connector on.
Step 3: Circuit
First, locate the wires attached to the connectors circuit (as shown) then remove them from the board. Then extend these allowing you to attach them more easily later (about 15cm of wire should work fine).
After extending the wires put together the circuit as shown in the images or download the Fritzing sketch.
Step 4: Hardware Box
After building the circuit glue it into place inside the project box (STL files in step 1) and make sure the keyboard connection wire pokes out one end and the micro USB is accessible through the hole in the other. I would also advise you to use a bit of hot glue around the wire to stop it from pulling from the circuit.
Then secure the box together with the 12mm M2.5 nuts & bolts and upload the code.
Step 5: Finishing
Now screw your keyboard back together, with the connector poking out where the connector used to be (as shown in image).
Then connect all of the pieces together and plug into your pc, and if you followed everything correctly it should work.