STM32H7 multi-channel ADC & DMA config help

[Mr. Berticus]

I'm having a very tough time getting more than 1 channel of an ADC instance using DMA to work on the Nucleo-H753 board. No matter what I try, nada... After rigorous debug, found that the ADC is NOT even starting when I call it to right before my while(1) loop... It saying that there is an internal error (17) and fails to start. This leads me to think that there's a config issue/error on my end. Any tips on setting up multiple ADC channels using DMA on the STM32H7 line would be greatly appreciated, as they have the fancier/more finicky 16b ADCs

[Pavel A.]

What have you tried? Maybe, following any ST examples?

[Mr. Berticus]

Yes, I've went through several examples, to no avail. Here's a snippet of my ADC config, main.c, and my CubeMX file. Please let me know if anything is setup wrong or if I'm missing something entirely. Many thanks in advance!

[Piranha]

https://community.st.com/s/question/0D50X0000Bmob3uSQA/dma-not-working-in-cubemx-generated-code-order-of-initialization

This is beyond ridiculous...

[Mr. Berticus]

What is "beyond ridiculus", the CubeMX's bugs; or the question I posted?

[Piranha]

The CubeMX, of course! The link I gave is not about bugs, but about a single bug which has not really been fixed in years, because it reappears again, and again, and again...

[Petr DAVID]

Hello Mr. Berticus,

have you been able to fix the problem? For clarification part of the problem of your code is linked to order of initialization of peripherals caused to a bug in STM32CubeMX as described in the thread posted by Piranha and solution described here. Further you initialize 2 channels, but in your code it seems you are interested in reading three channels and at last you are not supposed to use HAL_ADC_GetValue. In case of using DMA the values supposed to be in the specified buffer that you have chosen in HAL_ADC_Start_DMA.

You supposed to define function void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc). That will be called each time the buffer is filled with the new values. This is described in this video.

Please let me know if I you will have further problems.

[Mr. Berticus]

Hi Petr DAVID,

I should've clarified initially that I was trying a multitude of different things to try to get this working. As of this morning, I haven't been able to get it working, unfortunately. I will follow your advice and let you know how it works out. Also, I believe there should be a pop-up window at time of project creation in CubeMX asking the user to verify the silicon rev (Y or V) of the micro on their Nucleo board before they begin. I wasn't aware that it even existed in the "RCC" tab, or that it was even an option... Idea for the next CubeMX release?

Thank you,

Mr. Berticus

[Pavel A.]

> I believe there should be a pop-up window at time of project creation in CubeMX asking the user to verify the silicon rev (Y or V)

This is not a popup window - at least not for STM32H7. The Y vs V stepping selection is in RCC -> system parameters.

[KStef.1]

For others who are facing issues with ADC with DMA, you need to be aware of the potential issues of using DMA on cached memory space. I cannot post the link here because I'm new, but you can search for "DMA is not working on STM32H7 devices". It is a knowledge article from ST.