Bare Metal Timer PWM generation using DMA

[DJ1]

Hi guys, Can anyone list out a few steps which need to be followed for bare-metal code generation of using Timer in DMA for PWM generation. 

Thanks!

[Sarim-Jalil]

Hi,

I am not sure if it will answer your query properly but I think this Timer + DMA + PWM  might help you.

[DJ1]

Hi thanks but i am looking for Bare-Metal approach of code rather than using HAL Libraries. Because in the reference manual there are no clear step for using Timer DMA

[Sarim-Jalil]

You can always explore the HAL function to know what they are doing that you need to do for bare metal to work.

[Sarra.S]

Hello @DJ1 , 

A similar question has been raised and answered by Jan, you may want to check it out here 

 

[DJ1]

Hi sarra, thanks but the thing is i am able to generate PWM using timers but not using timer DMA. If you can help me that !

[Issamos]

Hello @DJ1 

This tutorial (guide + vidéo) is downing exactly what you are looking for.PWM with DMA in STM32.

Best regards.

II

[Johi]

I made some examples in LL_ instead of HAL_ is LL_ ok for you or not "Bare metal" enough?

[waclawek.jan]

What *exactly* do you want to do? Details matter.

On what STM32?

What do you already have?

JW

PS. Maybe have a look at "breathing" demo (table-driven version, as the other one is slightly crazy) here.

[DJ1]

Hi, so the thing is earlier i tried on how to increase the clock frequency using PLL through bare metal coding/scratch. Now i want to use timers for generating PWM using DMA. So what would be the steps to follow for using PWM with DMA that to coding from scratch/using register without using HAL libraries. I went through the HAL_TIM_PWM_Start_DMA function but could not get much through it.

I also tried developing code through registers but in that the PWM is not generating.

[LCE]

HAL stuff is hard to read and get through, but (most of) it works.
So you just need lots of concentration and perseverance...

When starting from scratch:
- read the RM
- "collect" relevant registers
- start simple: no settings, just a fixed frequency & duty cycle square
- then add stuff...

PS: DMA is one of the few things I use HAL, many of the HAL_DMA_Start functions are quite "slim" compared to the normal HAL stuff

[waclawek.jan]

Which STM32?

> I also tried developing code through registers but in that the PWM is not generating.

Show.

JW

PS. +1 to what @LCE  wrote above.