The USB module will provide a gateway between the USB MIDI transport and the CAN bus. Which means it needs to support both MIDI 1.0 and 2.0 over USB. This module also has an ADC and a DAC, both having 24-bits resolution and two channels for stereo. This let's it act as an audio interface so audio can be sent between the modular and a DAW. The schematics and PCBs can be viewed on CADLab.

This module can act both as a USB device, and as a host. There is a TUSB320 chip handling the USB-C direction logic, so the microcontroller behaves like a USB-OTG device. Devices connected to the port can draw up to 500mA, otherwise a powered hub would be needed.

The top-side contains mostly analog circuits, like the opamps, ADC, and DAC.

This PCB was mounted orthogonal to the front-plate, because it makes the module slimmer. The 3.5mm jacks are holding these boards together. This module has a 4-layer PCB to make the routing more compact, because deep modules won't fit in some eurorack cases.

The bottom-side contains digital circuits like the microcontroller, and CAN circuits.