Chris Kann
Prototype board
The approach I took is possibly the simplest way to deal with it all. Using shift registers in and out along with a PIC18Fxxx (clocked at 10mhtz the CPU clock rate divides nicely for MIDI use of the PIC's USARTs at 31250 baud).
Basically you strobe / latch the registers, then shift them into the PIC and take a look at whats on the lines. For the keyboard I also use a 74xx138 for dealing with the matrix.
I had to modify I think one or two lines on the keyboard pcb (trying to remember its been a few years). To use this kind of setup.
I decided to keep the power supply on this PCB, afterall theres plenty of room left over, especially after I route a new PCB with surfacemount components.
I'm probably going to add an external NVRAM or FLASH chip since the PIC18F internal memory is pretty small unless you start using the program space.
The clunky (way overrated wattage) 1% resistors are 100k pullups.
Prototype board
The approach I took is possibly the simplest way to deal with it all. Using shift registers in and out along with a PIC18Fxxx (clocked at 10mhtz the CPU clock rate divides nicely for MIDI use of the PIC's USARTs at 31250 baud).
Basically you strobe / latch the registers, then shift them into the PIC and take a look at whats on the lines. For the keyboard I also use a 74xx138 for dealing with the matrix.
I had to modify I think one or two lines on the keyboard pcb (trying to remember its been a few years). To use this kind of setup.
I decided to keep the power supply on this PCB, afterall theres plenty of room left over, especially after I route a new PCB with surfacemount components.
I'm probably going to add an external NVRAM or FLASH chip since the PIC18F internal memory is pretty small unless you start using the program space.
The clunky (way overrated wattage) 1% resistors are 100k pullups.