I'm using the Nucleo STM32G474RTE board and the LL drivers for DMA, GPIO and HRTIM and the CUBEMX in the IDE. My goal here is to drive a full H-Bridge with 4 PWM signals having the needed deadband and duty cycle control.
Using the LL libraries and CUBEMX in the IDE, I have this working using the HRTIM master timer and timers A and B driven by the master timer and inserting deadtime -- just what I need:
LL_HRTIM_TIM_SetCompare1(HRTIM1, LL_HRTIM_TIMER_MASTER, myDutyCount);
However, I want to automate the duty cycle updates once each PWM period using DMA from a circular buffer. How do I do this?
This would seem to be a standard thing to do, yet there are no examples of exactly this. The TIM_DMA_Init example uses Tim1, but the HRTIM Master Timer seems to be very different. For instance, in the example there is this line of code:
LL_DMA_ConfigAddresses(DMA1, LL_DMA_CHANNEL_5, (uint32_t)&aCCValue, (uint32_t)&TIM1->CCR3, LL_DMA_GetDataTransferDirection(DMA1, LL_DMA_CHANNEL_5));
I've tried with no success to modify this line of code to provide the DMA with the Master Timer's compare 1 register as its destination.
Anyway, I want to drive a full bridge with 4 synchronized high resolution PWM signals having deadtime and duty cycle control, where the duty cycle is simultaneously updated for all 4 PWM via DMA from a circular buffer. Perhaps someone with more experience knows a better way to use the HRTIM for this? I'm not using Timers A-F for anything else so they are free to be used here. Is there an app note that directly addresses this basic application? I'm new to ST Micro -- the docs and parts are excellent so far, but this has me stumped and frustrated.
