Reset forced low

[fcasa.16]

Hi,

while the software are working, suddenly it will become stop, and reset pin is permanently forced low, it freaks me out!! Someone will help me, thank you so mutch

[Javier1]

what do you mean with permanently?

[fcasa.16]

Thank you Javier

reset pin goes to 0 Volt and doesn't work until the power is off. It seems to be frozen.

this appens especially when we are getting strong electric interference

[fcasa.16]

Thank you Javier

reset pin goes to 0 Volt and doesn't work until the power is off. It seems to be frozen.

this appens especially when we are getting strong electric interference

[Javier1]

@fcasa.16​ maybe show us some pictures/schematics or explain a little bit more your issue.

[WilkoL]

And the GPIO next to the RESET pin?

Also, what chip do you use? On some you can change the RESET pin into PA1.

[fcasa.16]

MCU: STM8L151C8T6 , below section of schematic, RESET, after power on, change in PA1 Output OD and SWIM change in PA0. I'm at my wits end

[WilkoL]

Is it possible to NOT re-use RESET and SWIM? Because my guess is that your problem has something to do with that. I never use those pins for anything else than programming and debugging. If I need more pins than available I upgrade to a bigger microcontroller.

So (if possible) see if the problem still happens when you don't do anything with PA0 and PA1.

[fcasa.16]

Unfortunately, problem still happen even if I not reuse reset and swim.

[WilkoL]

Without having the pcb and code here it is hard to guess. It can be all sorts of things, floating GPIO doing strange things, a short between another pin and the RESET line, an error in the code causing the RESET to be pulled low...

Single stepping through the code isn't possible I think, because you said the microcontroller will work for a while, you might be single stepping for ages. Maybe logging things, for example by sending data out via a uart and recording it with Notepad++ will give you some clues.