Brian Dorsey

Hi USB & electronics folks! Recommendations for analyzing USB traffic from an embedded device?

I have a device (audio recorder) which hosts USB keyboards. Works fine with several keyboards. Doesn't work when I emulate a keyboard with Circuit Python or Arduino code based on examples (which work connected to computers)

What would you recommend putting between them to record working sessions to learn how to make it work? Willing to invest money in gear.

#USB #embedded

Apr 17, 2024 at 3:04amWeb
Show threadBrian DorseyApr 18, 2024
I ended up pre-ordering this: https://www.crowdsupply.com/great-scott-gadgets/cynthion
Cynthion

A multi-tool for building, analyzing, and hacking USB devices

Crowd Supply
Show threadBenderRobotApr 17, 2024
@briandorsey you can check out picoscope, they seem to have an analyzer function for that. https://www.picotech.com/library/oscilloscopes/usb-serial-bus-decoding
#picoscope #oscilloscope #electronics
USB - Serial bus decoding | Pico Technology

The evolution of USB serial bus decoding has allowed PicoScope 6 to decode many USB serial bus protocols.

Show threadAndreas BombeApr 17, 2024

@briandorsey Don't know about USB analyzers, but maybe the reason it doesn't work.

There are two protocols for USB keyboards (and mice, I think), the normal full feature one and a simpler "boot" protocol meant for BIOSes to be able to support USB keyboards with less complex driver code.

Possibly the host device supports only one of these and the CircuitPython code you tried only offers the other.