It reports on USB with idVendor:idProduct of 1a86:5537, and the device name "QinHeng Electronics WCH32 Virtual COM Port". But it is not actually a COM port (at least I don't think it is).
This code can upload an arbitrary message to the device. The device must be powered off (fan not spinning) for the upload to work.
Original software is in assets/. There are two versions:
- older, which based on my reverse engineering knows how to talk to idVendor:idProduct 0c45:7160; this is also uploaded to archive.org
- newer that knows how to handle 1a86:5537.
This repository handles only 1a86:5537, but it probably can be made to work with 0c45:7160. I suspect the message format is identical.