I have a broken Technics PX-103 e-piano, or more precise the piano without most of the electronics. Still there is the keyboard along with its board for scanning the keys.
What I'd like to have in the end would be midi output for the keyboard (and maybe the pedals but this shouldn't be hard).
Instead of scanning the keys by hand I hoped I could use the existing gate array and connect it to a (atmega16) micro controller from where I can read out the key states and do the processing to note on/off messages.
The gate array's connection is shown in thisservice manual (edit: correct link) on page 27 C1/2.
The board also contains an EEPROM (1 kb) whose purpose I don't understand (maybe to identify the board from the control board).
As the pins in the service manual are labled rather clear (data, request, !reset, acknowledge, ready and value) I hoped to be able to more or less easily access the key states.
Having connected the pins and written a program to remotely set the outputs and read the inputs I was able to read some data which at least depends on different output bit settings. The ready bit is never set though, and I also must also admit that I'm not sure which purpose the value input should have.
Of course, I could alternatively do the scanning by hand but if possible, I'd like to use the existing gate array.
So after this not too short text my question would be if anyone has any info about how the gate array should be addressed and also if this is a feasible approach in the first place.
Edit: fixed link to service manual which only was the normal manual.
What I'd like to have in the end would be midi output for the keyboard (and maybe the pedals but this shouldn't be hard).
Instead of scanning the keys by hand I hoped I could use the existing gate array and connect it to a (atmega16) micro controller from where I can read out the key states and do the processing to note on/off messages.
The gate array's connection is shown in this
The board also contains an EEPROM (1 kb) whose purpose I don't understand (maybe to identify the board from the control board).
As the pins in the service manual are labled rather clear (data, request, !reset, acknowledge, ready and value) I hoped to be able to more or less easily access the key states.
Having connected the pins and written a program to remotely set the outputs and read the inputs I was able to read some data which at least depends on different output bit settings. The ready bit is never set though, and I also must also admit that I'm not sure which purpose the value input should have.
Of course, I could alternatively do the scanning by hand but if possible, I'd like to use the existing gate array.
So after this not too short text my question would be if anyone has any info about how the gate array should be addressed and also if this is a feasible approach in the first place.
Edit: fixed link to service manual which only was the normal manual.
