Commented with the relevant PRs over here: viewtopic.php?t=394730 but to help those in the future who stumble upon this:
pico-sdk PR: https://github.com/raspberrypi/pico-sdk/pull/2764
Pico-PIO-USB PR (the example code): https://github.com/sekigon-gonnoc/Pico-PIO-USB/pull/195
The example works now, implementing two CDC interfaces (plus reset interface) on the device (computer-facing) side, and offering USB host support on the PIO-USB interface which can use a USB hub and supports connecting any two CDC devices.
on the device side, the first CDC port is your usual sdio interface (printf(), etc.) and any data that the first CDC device connected on the pico's host port is dumped (hex dump) here. The second CDC port on the device side is a "transparent mirror" with the second CDC device connected on the pico's host side -- e.g. if you open port #2 on your computer you can transmit data to whatever the second serial device you connected, and whatever that device sends you'll see.
pico-sdk PR: https://github.com/raspberrypi/pico-sdk/pull/2764
Pico-PIO-USB PR (the example code): https://github.com/sekigon-gonnoc/Pico-PIO-USB/pull/195
The example works now, implementing two CDC interfaces (plus reset interface) on the device (computer-facing) side, and offering USB host support on the PIO-USB interface which can use a USB hub and supports connecting any two CDC devices.
on the device side, the first CDC port is your usual sdio interface (printf(), etc.) and any data that the first CDC device connected on the pico's host port is dumped (hex dump) here. The second CDC port on the device side is a "transparent mirror" with the second CDC device connected on the pico's host side -- e.g. if you open port #2 on your computer you can transmit data to whatever the second serial device you connected, and whatever that device sends you'll see.
Statistics: Posted by anotherandrew — Fri Dec 19, 2025 11:37 pm