why does ADC_FLAG_EOS get called after each channel?

[Scott Dev]

Posted on April 06, 2017 at 12:22

Hi

I am trying to use the ADC in the STM32L07 as a multichannel scan. I have set up Cube for 3 analogue channels, AN0, Temperature and VRef Int. I have set it up for single scan usign the HAL_ADC_Start_IT(&hadc); command. Within the interupt routine I am checking the ADC_FLAG_EOC for after each channel completed, and the ADC_FLAG_EOS for after the complete scan is completed. When the HAL_ADC_Start_IT is called, I see the first channel with ADC_FLAG_EOC, but straight away the ADC_FLAG_EOS is also called. I am new to the chip, and not sure what I am doing wrong, can anyone advice me? My code is below, and attached is snap shot of the cube setting

Many Thanks

Scott

unsigned ADC_Raw[3];

unsigned char ADC_index=0; #define AD_VCCINT 2 #define AD_TEMP 1

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

{ if (__HAL_ADC_GET_FLAG(hadc, ADC_FLAG_EOC)) { ADC_Raw[ADC_index++]=HAL_ADC_GetValue(hadc); ADC_raw = HAL_ADC_GetValue(hadc); } if (__HAL_ADC_GET_FLAG(hadc, ADC_FLAG_EOS)) { <<gets called straight after first conversion... ADC_index=0; Vdd = 3000 * (*VREFINT_CAL_ADDR)/ADC_Raw[AD_VCCINT]; temperature=(((int32_t)ADC_Raw[AD_TEMP]*Vdd/3000)-(int32_t)*TEMP30_CAL_ADDR); temperature*=(int32_t)(130-30); temperature/=(int32_t)(*TEMP130_CAL_ADDR - *TEMP30_CAL_ADDR); temperature+=30; } }

static void MX_ADC_Init(void)

{

ADC_ChannelConfTypeDef sConfig;

/**Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)

*/ hadc.Instance = ADC1; hadc.Init.OversamplingMode = DISABLE; hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1; hadc.Init.Resolution = ADC_RESOLUTION_12B; hadc.Init.SamplingTime = ADC_SAMPLETIME_1CYCLE_5; hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD; hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT; hadc.Init.ContinuousConvMode = DISABLE; hadc.Init.DiscontinuousConvMode = DISABLE; hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START; hadc.Init.DMAContinuousRequests = DISABLE; hadc.Init.EOCSelection = ADC_EOC_SINGLE_SEQ_CONV; hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED; hadc.Init.LowPowerAutoWait = DISABLE; hadc.Init.LowPowerFrequencyMode = DISABLE; hadc.Init.LowPowerAutoPowerOff = DISABLE; if (HAL_ADC_Init(&hadc) != HAL_OK) { Error_Handler(); }

/**Configure for the selected ADC regular channel to be converted.

*/ sConfig.Channel = ADC_CHANNEL_0; sConfig.Rank = ADC_RANK_CHANNEL_NUMBER; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { Error_Handler(); }

/**Configure for the selected ADC regular channel to be converted.

*/ sConfig.Channel = ADC_CHANNEL_TEMPSENSOR; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { Error_Handler(); }

/**Configure for the selected ADC regular channel to be converted.

*/ sConfig.Channel = ADC_CHANNEL_VREFINT; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { Error_Handler(); }

}

Note: this post was migrated and contained many threaded conversations, some content may be missing.

[Scott Dev]

Posted on April 06, 2017 at 18:11

Its a strange one. I have also tried what you suggested, just set ADC_EOC_SINGLE_CONV and it just carried out one conversion. Also tried ranking 1,2,3.  I only called HAL_ADC_Start_IT(&hadc) once. So looks like for some reason its not sampling the other 2 channels.

Scott

[howard n2wx]

Posted on April 06, 2017 at 19:17

Does changing

hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;

to

hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD | ADC_SCAN_ENABLE;

fix it?

[Scott Dev]

Posted on April 07, 2017 at 16:12

Hi

 Anyone had the same issue? I have went through the example many times and still get the same result.

Regards

Scott

[egarcia]

Posted on April 07, 2017 at 20:18

Hi Scott:

I was also doing development, actually following the same example you are, and had the same issue!

On the debugger, I was following your same steps. When you hit your first breakpoint, do you also get an OVR flag set on the ISR register? I noticed I was, which I believe it means that the ADC is going faster than the interrupt can handle it. Maybe the interrupt overhead of CubeMX's code?

Anyway, I changed the clock to 'Synchronous Clock Mode / 4' and tried it again. If I put the breakpoint on the 'if (__HAL_ADC_GET_FLAG(hadc, ADC_FLAG_EOS))' code block I can get the values of the three channels. However a breakpoint on the other 'if' block will make the ADC overrun.

Let me know if this helps, I hope it does!

Thanks,

-Eduardo

[Scott Dev]

Posted on April 09, 2017 at 18:47

Hi Eduardo

  Thanks for your reply, and a great help, cheers.

What you said is exactly what i am seeing. I am new to the STM32 , so still learning .I would have never throught of that one,as I always assumed as I was using the debugger everything would stop between breakpoints and wouldnt get OVR set. I have set the same as you with the clock mode /4 . But also had to slow down the ADC sample rate or still wouldnt work. I thought this was the speed between the each sample period, and nothing to do with each channel. 

I like the CubeMX, but maybe its becasue I am new to this , but does save a lot of time. I might try setting the ADC up without using the CubeMX to see if this works without changing these settings.

Thanks Again

Scott

[Imen.D]

Posted on April 10, 2017 at 18:43

Hi

devlin.scott

,

Regarding

ADC_EOC_SINGLE_SEQ_CONV use, this is already answered by

Joly.Jeanne

in

https://community.st.com/0D50X00009Xkf0fSAB

For your second point regarding

ADC_EOC_SINGLE_SEQ_CONV, it is a feature possible on HW side but, since a couple of years, we did not findany use case in SW in the HAL driver. We use eitherADC_EOC_SINGLE_CONV orADC_EOC_SEQ_CONV. With your post, as this variable is not use, we decided to delete this variable. It will be as well available in the nextCubeMX release.

Hope this helps you.

Imen

[Scott Dev]

Posted on April 13, 2017 at 19:15

Hi Imen

  Thanks for your replies. I have set the ADC to only convert 1 channel at a time, and call HAL_ADC_Start_IT(&hadc); to start the convertion.  What I am seeing is that the

ADC_EOC_SINGLE_CONV

does get called after each channel ,and I call HAL_ADC_Start_IT(&hadc); to start the next channel. Then when all 3 have been converted, the

ADC_EOC_SEQ_CONV does get called. Mind, as I probably dont need it as after the each

ADC_EOC_SINGLE_CONV

I can work out when all convertions are comlpeted.

Scott

[gates.nathan]

Posted on June 07, 2017 at 20:30

Hi

devlin.scott

‌ have made any progress on this it?

I have tearing my hair out trying to get read multiple channels using interrupts.

Im getting the same behaviour that you got: EOC flag followed directly after EOS flag.

Thanks

Nathan

[Scott Dev]

Posted on June 08, 2017 at 19:09

Hi Nathan,

 I never really got around the issue, but I dont the following:

I have 2 a/d channels and started sampling within my main() appliction with a HAL_ADC_Start_IT(hadc); and set ADC_index=0. When I get a EOC, I simply call HAL_ADC_Start_IT() again until all channels are read.

void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)

{    if (__HAL_ADC_GET_FLAG(hadc, ADC_IT_EOC))  //received EOC       {            ADC_Raw[ADC_index++]=HAL_ADC_GetValue(hadc); //store value and increase channel                if(ADC_index<3) //while not all channels read, start another interupt                HAL_ADC_Start_IT(hadc);

        }

        if (__HAL_ADC_GET_FLAG(hadc, ADC_IT_EOS))

        {         /.......        }    }

Regards

Scott

[Scott Dev]

Posted on June 08, 2017 at 23:41

Ooops, typo error. I meant to say,' I do the following'.  Instead of starting the interupt and end on a ADC_IT_EOS, I simply keep starting an interupt within the ADC_IT_EOC until all the channels are sampled. It would be great if someone managed to get this working.

Scott