About TCloe.1

TCloe.1 · 2021-10-23

Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved?STM32F411 I am trying to set up an example project for ADC with DMA using HAL library.I am sampling a slow ramp function from 0-...

TCloe.1 · 2021-10-25

Thank you this was the issue.

TCloe.1 · 2021-10-23

The gist of the code is as follows:ADC_HandleTypeDef hadc1;DMA_HandleTypeDef hdma_adc1;uint16_t adcVal[10];int main(){ HAL_Init(); SystemClock_Config(); MX_GPIO_Init(); MX_ADC1_Init(); MX_DMA_Init(); HAL_ADC_Start_DMA(&hadc1, (uint32_t*)adcVal, 10); ...

TCloe.1 · 2021-10-23

Correct, I missed that. Thank youS4CR_DMEIE and S4CR_TEIE are set, additionally S4CR_TCIE is set after a full conversion has been done.

TCloe.1 · 2021-10-23

Hi TDK, I agree that transferring the full word is wasteful, I will change this to half-word going forward.When debugging, I am using CubeIDE's Expressions view to look at the buffer values after each conversion. - I hope this answers you question.

TCloe.1 · 2021-10-23

Thanks for the reply;So I initialised the buffer with an impossible value as you suggested.The DMA does not populate the buffer at all, the buffer stays unchanged.So looking at the DMA2 register, the S2CR register is completely clear during debugging...

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Why is ADC result 8 bits when DMA is used, but the full 12-bits without DMA ?

Re: Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved. - STM32F411

Re: Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved. - STM32F411

Re: Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved. - STM32F411

Re: Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved. - STM32F411

Re: Why would an ADC sample in 8-bit mode when DMA is used, but when used without DMA the full 12-bit conversion is retrieved. - STM32F411