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Reset forced low

fcasa.16
Associate II

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

10 REPLIES 10
Javier1
Principal

what do you mean with permanently?

we dont need to firmware by ourselves, lets talk
fcasa.16
Associate II

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

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

we dont need to firmware by ourselves, lets talk
WilkoL
Senior

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
Associate II

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

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
Associate II

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

WilkoL
Senior

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.