Hi, i recently buyed a Akai MPD226… i hoped i could use it standalone with MIDI-TRS/DIN Hardware… but LED Feedback doesnt work (aka Notes from a Hardware Sequencer give no Response to the PADS)
- short the Akai Firmware sucks.
I made a teardown, searched on the MPC-Stuff website… and made PAD-Footprints for KICAD, made shematic and so on:
Result: OpenPAD
I dont use the same shematic as Akai did… the multiplexed 4 Inputs of a STM32F103 with some HC595. My goal is to use 2x MCP3208 and connect them without switching to the PADs.
SO I HAVE A QUESTION:
the akai Resistive Foil - has a resistance from 280 Ohm if you measure diagonal between the corners.
Our MCP3208 wants 0-5V.
How do i limit the current going thru the Foil, without reducing the 0-5V Range?
OP-Amps? how? Thx 4 Input
I too have drawn a Core PCB 4 Pick and Place… incl STM32F407VGT6 
