how does a keyboard work?

[syamajala]

I have two old electronic casio keyboards that i don't use and was considering building a midi controller out of one of them, but i've been wondering how the keys in a keyboard work. If the keys are velocity sensitive would they be used as analog inputs for a core? If not, then I would assume they are digital inputs correct? Does the velocity sensitivity depend on the actual key or is something fancy thats done in software? I don't know if this project will actually culminate in anything useful, but its something i've been a bit curious about and have had a hard time finding info on.

[clem!]

Hi syamajala,

in short:

in a non-velocity-kb you will find one contact for every key. If a key is pressed normally velocity=64 is transmitted. In a velocity-sensitive-kb you will find two contacts that close with a short delay. The time between closing those two contacts is measured and outputted as velocity-byte. The shorter the time - the bigger the value of the velocity byte.

You can read something about it in old doepfer-manuals for example for the LMK3 at their homepage. If you read the threads under midification (where to my mind this post belongs too), you will find some more infos.

Best regards,

clem!