SIG TRAP on STM32F103CBT6TR

suba512 · ‎2026-03-20

I am working on a custom board with STM32F103CBT6TR. Initially, flashing the code resulted in a Hard Fault error, but now it consistently enters a SIGTRAP even after removing all breakpoints. Additionally, the GPIO pins are not toggling as expected. The code is attached as notepad file for reference. Can someone give a solution to this, thank you.

suba512 · ‎2026-03-22

I will see to try on this and will update you. Thank you.

Andrew Neil · ‎2026-03-23

@suba512 wrote:
I tried in NUCLEO-H753ZI development board too,

That's a completely different chip - really doesn't tell you anything about the behaviour of an STM32F103 !

You could try this utility to see what is actually on your Blue Pill:

https://mecrisp-stellaris-folkdoc.sourceforge.io/bluepill-diags-v1.640.html#diags-1-640

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

suba512 · ‎2026-03-23

I will see to it and will update you regarding this, thank you.