rust-stm32/docs/troubleshooting.md

Troubleshooting

Probe Not Found

• Run probe-rs list.
• Check USB cable and power.
• Check SWDIO, SWCLK, GND, and 3V3.

Linux Udev Permissions

• You may need udev rules for ST-Link or your probe.
• Install the vendor or distro rules, then replug the probe.

Wrong Chip Selected

• Run probe-rs chip list | rg STM32F103.
• Override the default with PROBE_RS_CHIP=STM32F103C8.

No Firmware Output

• Use run-04 or run-08 from nix develop.
• Confirm the firmware did not crash early.
• Confirm the probe stays attached.
• Confirm BOOT0 is low.

Host Chapter Does Not Run

• Use run-00, run-01, run-02, or run-03.
• If you skipped Nix, make sure rustup toolchain install 1.95.0 and rustup target add thumbv7m-none-eabi are done.
• If you skipped Nix, make sure flip-link is on your PATH for embedded builds.

Blue Pill LED Looks Inverted

• That is expected on most boards.
• PC13 is usually active-low, so driving it low turns the LED on.

Safety

• Check board voltage before connecting anything.
• Check SWDIO, SWCLK, GND, and 3V3 wiring before flashing.
• Do not assume a random button or LED pinout without checking the board.

Contribution

• Keep nix develop, fmt, check, and the chapter build or run aliases working.
• Document hardware assumptions when they matter.
• Do not claim hardware-tested behavior unless it was actually tested on hardware.