For the keyboard, instead of using some parallel/serial keypad I chose to dismantle an old keyboard I had and use its key decoder chip, so as you can see in the photos, I just connected some simple push buttons in the places where the keyboard keys would normally be and mounted them to the front of mp3ophono. I didn't solder the cables directly to the motherboard so that I can easily disconnect the "custom keyboard" (i.e. the front keys) and connect a normal keyboard .

Here is a schematic:

When two of the flat-cable cables make contact, then a key is reproduced. Of course not all of them produce a key, I did the mapping by examing the membrane of the original keyboard. It's rather simple. The keys in my device are connected as follows (look at the pictures and read the README):
Note: Your keyboard may not look like this. I have no idea what brand of keyboard to use, just try opening some and see for yourself.


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