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Linas L
Senior
April 17, 2021
Solved

STM32L412 GPIO toggle from hardware without using dedicated timer as AF on that pin

  • April 17, 2021
  • 3 replies
  • 898 views

Hello,

I run into problem for selecting TIM2 as my pwm output. As it turns out, it is only output capable. But I need to get processor independent 3kHz 50:50 PWM signal with no AF functional PWM.

Any simple idea how can I toggle with 50% 3kHz duty cycle this GPIO? (PA15 on STM32L412C8)

I Am thinking of using DMA, just have no idea how to do that, since I can't use ODR register,I have multiple pins that should not change, and with BRR BSRR, well, it is two address, so what ? Do ping pong DMA with single transfer and circular buffer ?

Any ideas are welcome :)

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Best answer by Linas L

Hi,

I found the problem, I was looking at LPTIM2 instead of TIM2

No problems in this case :) Thank you all !

3 replies

Uwe Bonnes
Chief
April 17, 2021

PA15 is TIM2_CH1and can do PWM . All other solutions wll give you at least Jitteror even missing cycles.

Linas L
Linas LAuthorBest answer
Senior
April 17, 2021

Hi,

I found the problem, I was looking at LPTIM2 instead of TIM2

No problems in this case :) Thank you all !

Piranha
Principal III
April 17, 2021

First, like Uwe already said...

Second, read what a BSRR register is. At least read it's name!