Does anyone know of an example showing SPI implemented with DMA on freeRTOS? I was not able to get this running. When I check the data variable in DMA2_Stream0_IRQHandler, it is always 0 when I expect it to be 1. I'm using the STM32F407G DISCO.

LMorr.3 · ‎2023-05-29

I have SPI set in Master Receive Mode Only and my code does work when not passing data to DMA.

Sarra.S · ‎2023-05-30

Hello @LMorr.3,

Have you checked the CubeFW example of SPI data buffer transmission and reception with DMA?

It's not with freeRTOS though

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LMorr.3 · ‎2023-05-30

Thanks, I'm looking at that sample code now. One issue is that I'm not clear on what libraries I should be using. HAL libraries are discouraged, which leave me with bare-metal. I wish someone would just post a simple explanation on how CMSISV1, CMSISV2, HAL, LL, and all the other 'libraries' work together and which ones are deprecated. Seems like a very messy approach grown over the years by folks who are way to deep to get a new-comer's eye view on getting setup. All official docs recommend HAL but then sample code now shows library usage I've not come across yet ( LL_ ) so I'll have to learn about that before I can proceed. Still not sure if I should now focus on coding with LL instead of bare metal, CMSIS or HAL.

LMorr.3 · ‎2023-05-30

To partly answer my own questions: HAL does not seem to support DMA for Master receive only mode. Its functions expect DMA to be setup for tx as well or exits with HAL_ERROR. Will look at using CMSIS to see if that helps.

Also, I think LL is no longer supported.

LMorr.3 · ‎2023-05-30

UPDATE:

I always see hdmarx status 'HAL_DMA_STATE_ABORT' in DMA2_Stream0_IRQHandler each time I call HAL_SPI_Receive_DMA(hspi,pData, Size)

Not sure what would cause that.

LMorr.3 · ‎2023-06-01

I am all set now, thanks!