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AndreaC1985
AndreaC1985
Associate II
June 26, 2018
Question

Dual regular simultaneous mode ADC triggered from timer 4 using DMA1

  • June 26, 2018
  • 6 replies
  • 3379 views
Posted on June 26, 2018 at 14:32

Hello all,

I have cube 4.25.1 installed and I'm using stm32f303 mcu.

What I have to do is to read 5 analog channels with ADC1 and 5 analog channel with ADC2 triggered from timer 4 counting.

I read application note An3116 and it said that it is possible to trigger simultaneus reading of sequence of channel.

0690X0000060LOWQA2.png

I used the cube configuration attached:

than after the hardware inizialization is performed the instruction below:

HAL_ADC_Start(&hadc2);

HAL_ADCEx_MultiModeStart_DMA(&hadc1, (uint32_t*)adc_array, sizeof(adc_array));

where adc_array is 32 bit array is a 5 item array.

Is there some error in the configuration or in the ADC start command?

Is there some software example using the new stm32 hal library?

Thanks

    This topic has been closed for replies.

    6 replies

    T J
    T J
    Senior III
    June 26, 2018
    Posted on June 26, 2018 at 15:51

    I am only using a single channel, but this is my init code

    typedef enum {

        Rs8_Ad1,

        Rs5_Ad5,

        Rs1_Ad6,

        Rs2_Ad7,

        Rs3_Ad8,

        Rs4_Ad9,

        CurrentSense_Ad13,

        Rs6_Ad14,

        Rs7_Ad15,

        VTemp_Ad16,

        VRef_Ad17,

        VBat_Ad18,

        ADC_ChannelCount,   // channels count

    } ADCresultsAveColumn_t;

        HAL_ADC_Start_DMA(&hadc, (uint32_t *)ADC_DMABuffer, ADC_ChannelCount);
    T J
    T J
    Senior III
    June 26, 2018
    Posted on June 26, 2018 at 15:59

    Your ADC DMA is set to transfer Words at 32bit, my code the DMA transfers Half-Words.

    I never used that processor sorry,

    but under ADC properties, ranking, with sampling at 1.5 cycles,

    that's as fast as it goes, it will be unstable and drifting around and incorrect.

    AndreaC1985
    AndreaC1985Author
    Associate II
    June 26, 2018
    Posted on June 26, 2018 at 16:30

    Hello TJ,

    when

    multimode.Mode = ADC_DUALMODE_REGSIMULT;

    I checked the post below and in order to start the conversion uses my same functions:

    https://community.st.com/0D50X00009XkY98SAF

    For the sampling time I can try to increase and Let you know the result.

    Regards

    AndreaC1985
    AndreaC1985Author
    Associate II
    June 28, 2018
    Posted on June 28, 2018 at 10:07

    somebody has some hints related to this problem?

    T J
    T J
    Senior III
    June 29, 2018
    Posted on June 29, 2018 at 01:46

    Hi, sorry to be a bit busy...

    Did you notice in your ICO file that the ADC config DMA is moving 32 bits ?

    it is supposed to be 16 bits...

    Are you seeing any data ?

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