Multiple ADC's and single conversion STM32F030

[mvugs9]

Posted on December 11, 2015 at 15:00

Hello

I'm having a hard time getting multiple ADC's working on a STM32F I have 3 analog voltages I would like to read with the MCU. But not continuous. I would like to take 1 sample at a time and at different intervals. I use the HAL library for this project and it seems very hard to select a channel and take a reading. I use CubeMX for the initialisation and this is what it returns:

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.ClockPrescaler = ADC_CLOCK_ASYNC;
hadc.Init.Resolution = ADC_RESOLUTION12b;
hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
hadc.Init.EOCSelection = EOC_SINGLE_CONV;
hadc.Init.LowPowerAutoWait = DISABLE;
hadc.Init.LowPowerAutoPowerOff = DISABLE;
hadc.Init.ContinuousConvMode = DISABLE;
hadc.Init.DiscontinuousConvMode = ENABLE;
hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc.Init.DMAContinuousRequests = DISABLE;
hadc.Init.Overrun = OVR_DATA_PRESERVED;
HAL_ADC_Init(&hadc);
/**Configure for the selected ADC regular channel to be converted. 
*/
sConfig.Channel = ADC_CHANNEL_1;
sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
sConfig.SamplingTime = ADC_SAMPLETIME_1CYCLE_5;
HAL_ADC_ConfigChannel(&hadc, &sConfig);
/**Configure for the selected ADC regular channel to be converted. 
*/
sConfig.Channel = ADC_CHANNEL_7;
HAL_ADC_ConfigChannel(&hadc, &sConfig);
/**Configure for the selected ADC regular channel to be converted. 
*/
sConfig.Channel = ADC_CHANNEL_8;
HAL_ADC_ConfigChannel(&hadc, &sConfig);
/**Configure for the selected ADC regular channel to be converted. 
*/
sConfig.Channel = ADC_CHANNEL_VREFINT;
HAL_ADC_ConfigChannel(&hadc, &sConfig);
}

Then in the main function I use this to retreive a sample:

/* USER CODE BEGIN 3 */
HAL_ADC_Start(&hadc);
HAL_ADC_PollForConversion(&hadc, 1000);
adcSample = HAL_ADC_GetValue(&hadc);
HAL_ADC_Stop(&hadc);
}
/* USER CODE END 3 */

But this always returns the value of adc_channel_1 on PA0 What is the correct way to retrieve a sample from another channel? My sincerely, #adc #hal #f0

[mvugs9]

Posted on February 16, 2016 at 20:11

I'm still not able to do single conversion on single channel. Is there a simple way to do adc conversion without the use of interrupts. Just polling between channels?

[f239955_stm1_st]

Posted on November 03, 2016 at 23:17

I'm having a similar problem. I thought that if I declared a ADC_ChannelConfTypeDef variable and called the HAL_ADC_ConfigChannel() function before trying to start the ADC and get a value, that might help, but I've not had any luck so far.

Talked to my friend and he said use DMA. However, it seems silly that HAL can't change channels.