Daisy as Audio USB device

Software Development
15

(Update) Edited the post to remove the assumption on whether it’s possible to make Daisy Seed support USB High-speed mode for high quality USB audio.

Hello all,

Thanks @antisvin for providing some information regarding USB support limitation on Daisy in this thread, which I think should be highlighted in this thread for anyone interested in utilizing USB audio support with Daisy:

  1. The USB port on Daisy seed board only supports full-speed operations (12Mbit/s) with on-chip PHY.
  2. USB 2.0 High-speed operation (480Mbit/s) is possible with external USB PHY, but none of the current daisy boards provide it.

References:

  1. AN4879 Application note: USB hardware and PCB guidelines using STM32 MCUs
  2. STM32H7 - USB OTG HS

In short, the USB audio support out of current Daisy boards are limited / crippled (despite Daisy boards provide 96k/24bit DAC chips, it’s limited to USB FS bandwidth). Not totally sure if a custom PCB with external PHY can make Daisy support USB HS but it doesn’t seem that Daisy Seed exported all the ULPI pins for USB OTG HS support.

Hope that helps!