Available as an assembled Module and as a DIY project.
This Module is currently available.
Power your USB devices with your Eurorack modular synth!
A tiny and simple 2 HP module to power any USB device using the power of your Eurorack:
Your power bus needs to have a 5V output for this module to work.
The module in itself doesn't provide any over-current protection so it's your responsibility to make sure you don't draw more current than what your power bus / power supply allow.
https://www.tindie.com/products/mentalnoise/usb-power-out-eurorack-module/