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GHrib.1
Associate III
December 23, 2022
Solved

Low voltage HIGH digital level of PWM signal on HRTIM_CHB outputs

  • December 23, 2022
  • 3 replies
  • 2197 views

I am using NUCLEO - G474RE and I am trying to use HRTIM to output some PWM signals. HRTIM_CHA output signals voltage levels are fine (0 - 3.3V). The problem is that the voltage levels of HRTIM_CHB are off. By measuring CHB (PA10/PA11) signals I get PWM signals with voltage levels of 0- 250mV. I measured CHB signals exactly at the output of the chip, so there is no way there is some kind of a divider on NUCELO. I assume something is puling down the outputs internally.

By examing GPIOA registers I found that there is no differnce in settings for CHA (PA8/PA9) and CHB (PA10/PA11):

Does anybody have an idea what is the problem?

This topic has been closed for replies.
Best answer by GHrib.1

I found that the outputs were actually deactivated. The low-voltage PWM that I measured with the oscilloscope was most likely caused by the EMI.

3 replies

Javier1
Principal
December 23, 2022

i would say you have a Hardware bug somewhere.

Is this a custom board? You could try the same with a nucleo

hit me up in https://www.linkedin.com/in/javiermuñoz/
GHrib.1
GHrib.1Author
Associate III
December 23, 2022

I am using NUCELO - G474RE.

GHrib.1
GHrib.1AuthorBest answer
Associate III
December 23, 2022

I found that the outputs were actually deactivated. The low-voltage PWM that I measured with the oscilloscope was most likely caused by the EMI.