STM32U545 : LPBAM cotinuous ADC multichannel

[Aurelien1]

Hi,

I am using an STM32U545 on which I expect to use ADC4_IN1 and ADC4_IN18 in stop mode 2 (using LPBAM).

I want to create two buffer (buff1 and buff2 uint16_t[32]) dedicated to each input.

I want to read 32 samples from input1 then 32 samples from input2 and restart infintely.

I don't find the correct way to configure LPBAM.

In first try, I use an LPTIM1 as trigger I do :

(sorry my project I can't get image of LPBAM configuration)

1) ADC conversion (channel 1) => ADC Conversion (channel 20) and loop on first conf bloc and use LPTIM1 trigger for both

    => In this case each buffer contain values from correct input but i run only once

2) If I do the same but loop on first data bloc => only last channel ise infinitrly sampled on both buffer

Can someone help me to configure it correctly?

Thanks

Have a good day.

Aurélien

[Sarra.S]

Hello @Aurelien1, 

One way is to use the DMA linked list to link the nodes and enable buffer chaining

=> check this presentation 

[Billy OWEN]

Hi @Aurelien1 

This post has been escalated to the ST Online Support Team for additional assistance.  We'll contact you directly.

Regards,

Billy

[Aurelien1]

Hi Sarra,

I will be on holiday starting tomorrow. I will try to look into it when I return. Regarding the LPBAM configuration, can you confirm if I need to create 3 queues:

• One for ADC conversion (channel 1).
• One for ADC conversion (channel 20 in my case).
• One for LPDMA.

For both queues, I configure the trigger on LPTIM to set the sampling data rate.

For LPDMA, if I don't set any trigger, will the queue switch between each DMA request at the end of the ADC conversion? Or should I use another timer to handle that switching?

I join a project whivh doesn't work (push button won't wake up device) I will correct this part when I come back.

Does the LPDMA and adc configuration is correct? (for this test I expect to connect debug probe in Hot Plug during the 10s sleep).

THanks for your help

Have a good day.

Aurélien

[Aurelien1]

Hi, do you have more information about channel switching in LPBAM?

To remind, I expect to get 32 samples of one channel before switching to the next one and so on.

[Aurelien1]

Is it possible to get an example? I am still unable to do it working...

Thanks for your help