This is an expander for Plinky that provides hardware MIDI in and out, along with 4 bipolar CV outs corresponding to paramteres A and B and accelerometer X and Y. Also provides a USB B Port*.
All SMD parts are preassembled, including panel LEDs and header. Very easy build, only 9 components need to be soldered.
Note: There are jumpers on the Plinky Expander, and how you want to use it will depend on which jumpers should be shorted.
JP1 and JP2 connect +12V and -12V from Plinky to the Plinky Expander. You almost certainly want to close these, unless you want to power Plinky and the Expander seperately, each with its own euro power cable.
JP3 connects 5V to the USB B connector, allowing the USB B to power Plinky.* If you plan on mounting both Plinky and Expander in a eurorack case, you likely want to leave this jumper open so you use your eurorack 5V source, and not your computers.
*The USB B port does not power Plinky properly, since a diode on Plinky V2 prevents this 5V source from feeding the buck boost converter to create +12V and -12V. If you plan on using Plinky and Expander standalone, and you wish to use the USB B port to power it, diode D4 on the Plinky main board needs to be shorted with a blob or a piece of wire. More talk about this on our Discord server.