The CH32V003 is a 10-cent RISC-V microcontroller with a proprietary single-wire debug interface and a corresponding proprietary debug dongle + modified version of OpenOCD.

My tool replaces the dongle and OpenOCD with a Pico-based GDB remote host. You can debug and flash a CH32V003 with just a Pico, one pull-up resistor, and gdb-multiarch.

Basic testing on the included example app seems to work, and the code should be stable enough to handle a few testers. If you're interested in the CH32V003 and have a Pico on hand, give it a try.

-Austin