[sdiy] Adding MIDI to cheap non-MIDI keyboard?

[Tom Wiltshire]

+1 agree with Benjamin. Decoding key contacts and producing midi notes is very simple.

> On 22 May 2026, at 02:37, Benjamin Tremblay via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I have had some luck scanning vintage toy keyboards. Cheapest way I know is to use the Arduino “mega pro mini” which is a miniature clone of the Arduino Mega . I see them for $10-20 online. It has lots of pins and multiple serial ports, and running at a full 5v seems to matter when scanning rubber buttons. Almost always these are an X *. Y matrix and the hard part is sorting out the pins/wires into which dimension each one belongs to. 
> Once you have a theory about how the pins work, write a tiny program to scan the pins where you set pins on “X” dimension high one at a time, and then read each “Y” pin to see if it’s high one at a time. If the circuit already has diodes, great, otherwise you may have to add diodes to support chords. 
> I’m lazy. Once I solder it up I just adjust a map in software until key numbers make sense .
> Benjamin Tremblay
> 
>> On May 21, 2026, at 9:14 PM, Didier Leplae via Synth-diy <synth-diy at synth-diy.org> wrote:
>> 
>> Does anyone have ideas about adding MIDI capability to a cheap keyboard that doesn’t have midi out? 
>> 
>> A friend of mine is interested in using a piano mat, made for kids, in performances, but these kinds of keyboards are very limited in their sounds. So, I wondered how feasible it would be to add a midi out.
>> 
>> <204980-z1.jpg>
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