RK-004 Raspberry Pi Image
Connecting the RPi to the RK-004 requires only 4 wires. The RPi Board will be powered from the RK-004. The PiZero will bolt right in with a straight connector but you can also use a flatcable to make the connection. Below is the pinout of the connector (the upper one with serial signals is for the RPi):
Note that this connector is not just for the RaspBerryPi. Although this is the platform we have released the code for, you can connect any board with serial I/O to it (arduino, etc) and communicate with your music gear.