2024-08-02 08:21 AM
Hello, I need help with ADC and DMA settings. My application is VERY EASY but I do not understand the setup parameters. The application is that I just start CPU and the ADC raw value should independently transfer via DMA to variable. When I need the value (randomly) I just read the internal variable. I saw several youtube manuals but I still have 0 on output even when there is 1V. I use PA0 pin (ADC1, chan 0) on very easy CPU STM32G031. I need to use DMA Channel 4 (Channel 1 and 2 are used for USART_RX and TX)
My setup:
The generated code is like this (I use LL):
static void MX_ADC1_Init(void)
{
/* USER CODE BEGIN ADC1_Init 0 */
/* USER CODE END ADC1_Init 0 */
LL_ADC_InitTypeDef ADC_InitStruct = {0};
LL_ADC_REG_InitTypeDef ADC_REG_InitStruct = {0};
LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
/* Peripheral clock enable */
LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_ADC);
LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);
/**ADC1 GPIO Configuration
PA0 ------> ADC1_IN0
*/
GPIO_InitStruct.Pin = LL_GPIO_PIN_0;
GPIO_InitStruct.Mode = LL_GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* ADC1 DMA Init */
/* ADC1 Init */
LL_DMA_SetPeriphRequest(DMA1, LL_DMA_CHANNEL_4, LL_DMAMUX_REQ_ADC1);
LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_4, LL_DMA_DIRECTION_PERIPH_TO_MEMORY);
LL_DMA_SetChannelPriorityLevel(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PRIORITY_LOW);
LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MODE_CIRCULAR);
LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PERIPH_NOINCREMENT);
LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MEMORY_INCREMENT);
LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_4, LL_DMA_PDATAALIGN_WORD);
LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_4, LL_DMA_MDATAALIGN_WORD);
/* USER CODE BEGIN ADC1_Init 1 */
/* USER CODE END ADC1_Init 1 */
/** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
*/
#define ADC_CHANNEL_CONF_RDY_TIMEOUT_MS ( 1U)
#if (USE_TIMEOUT == 1)
uint32_t Timeout ; /* Variable used for Timeout management */
#endif /* USE_TIMEOUT */
ADC_InitStruct.Clock = LL_ADC_CLOCK_SYNC_PCLK_DIV2;
ADC_InitStruct.Resolution = LL_ADC_RESOLUTION_12B;
ADC_InitStruct.DataAlignment = LL_ADC_DATA_ALIGN_RIGHT;
ADC_InitStruct.LowPowerMode = LL_ADC_LP_MODE_NONE;
LL_ADC_Init(ADC1, &ADC_InitStruct);
LL_ADC_REG_SetSequencerConfigurable(ADC1, LL_ADC_REG_SEQ_CONFIGURABLE);
/* Poll for ADC channel configuration ready */
#if (USE_TIMEOUT == 1)
Timeout = ADC_CHANNEL_CONF_RDY_TIMEOUT_MS;
#endif /* USE_TIMEOUT */
while (LL_ADC_IsActiveFlag_CCRDY(ADC1) == 0)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
Error_Handler();
}
}
#endif /* USE_TIMEOUT */
}
/* Clear flag ADC channel configuration ready */
LL_ADC_ClearFlag_CCRDY(ADC1);
ADC_REG_InitStruct.TriggerSource = LL_ADC_REG_TRIG_SOFTWARE;
ADC_REG_InitStruct.SequencerLength = LL_ADC_REG_SEQ_SCAN_DISABLE;
ADC_REG_InitStruct.SequencerDiscont = LL_ADC_REG_SEQ_DISCONT_DISABLE;
ADC_REG_InitStruct.ContinuousMode = LL_ADC_REG_CONV_CONTINUOUS;
ADC_REG_InitStruct.DMATransfer = LL_ADC_REG_DMA_TRANSFER_UNLIMITED;
ADC_REG_InitStruct.Overrun = LL_ADC_REG_OVR_DATA_PRESERVED;
LL_ADC_REG_Init(ADC1, &ADC_REG_InitStruct);
LL_ADC_SetOverSamplingScope(ADC1, LL_ADC_OVS_DISABLE);
LL_ADC_SetTriggerFrequencyMode(ADC1, LL_ADC_CLOCK_FREQ_MODE_HIGH);
LL_ADC_SetSamplingTimeCommonChannels(ADC1, LL_ADC_SAMPLINGTIME_COMMON_1, LL_ADC_SAMPLINGTIME_1CYCLE_5);
LL_ADC_SetSamplingTimeCommonChannels(ADC1, LL_ADC_SAMPLINGTIME_COMMON_2, LL_ADC_SAMPLINGTIME_1CYCLE_5);
LL_ADC_DisableIT_EOC(ADC1);
LL_ADC_DisableIT_EOS(ADC1);
/* Enable ADC internal voltage regulator */
LL_ADC_EnableInternalRegulator(ADC1);
/* Delay for ADC internal voltage regulator stabilization. */
/* Compute number of CPU cycles to wait for, from delay in us. */
/* Note: Variable divided by 2 to compensate partially */
/* CPU processing cycles (depends on compilation optimization). */
/* Note: If system core clock frequency is below 200kHz, wait time */
/* is only a few CPU processing cycles. */
uint32_t wait_loop_index;
wait_loop_index = ((LL_ADC_DELAY_INTERNAL_REGUL_STAB_US * (SystemCoreClock / (100000 * 2))) / 10);
while(wait_loop_index != 0)
{
wait_loop_index--;
}
/** Configure Regular Channel
*/
LL_ADC_REG_SetSequencerRanks(ADC1, LL_ADC_REG_RANK_1, LL_ADC_CHANNEL_0);
LL_ADC_SetChannelSamplingTime(ADC1, LL_ADC_CHANNEL_0, LL_ADC_SAMPLINGTIME_COMMON_1);
/* USER CODE BEGIN ADC1_Init 2 */
/* USER CODE END ADC1_Init 2 */
}
static void MX_DMA_Init(void)
{
/* Init with LL driver */
/* DMA controller clock enable */
LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);
/* DMA interrupt init */
/* DMA1_Channel1_IRQn interrupt configuration */
NVIC_SetPriority(DMA1_Channel1_IRQn, 0);
NVIC_EnableIRQ(DMA1_Channel1_IRQn);
/* DMA1_Channel2_3_IRQn interrupt configuration */
NVIC_SetPriority(DMA1_Channel2_3_IRQn, 0);
NVIC_EnableIRQ(DMA1_Channel2_3_IRQn);
/* DMA1_Ch4_5_DMAMUX1_OVR_IRQn interrupt configuration */
NVIC_SetPriority(DMA1_Ch4_5_DMAMUX1_OVR_IRQn, 0);
NVIC_EnableIRQ(DMA1_Ch4_5_DMAMUX1_OVR_IRQn);
}
But how can I setup the variable where is the ADC result saved?
How can I start the ADC?
I tried to use ADC1->CR |= ADC_CR_ADSTART; and reading ADC1->DR; but only zeroes...
Thank you
2024-08-05 04:25 AM
My signal is current feedback from the triac controlled motor. When I switch on the triac, I start to find maximum/minimum (it is offseted to 3.3V/2) current peak to check overtorque.
So it is 100Hz half-period and ever half period I need to find maximum/minimum value.
1kOhm output impedance with + 100nF on the input is maybe acceptable (?)
2024-08-05 05:25 AM
No, 100n too much here. But some cap you should have here, because you might get spikes from switching.
Maybe 2...10nF could be fine. And some protection of the adc input ... in case a big pulse coming... .
Just check with scope, adc input not yet connected, that signal is as expected and in range for adc.
2024-08-05 05:28 AM
It is OK, it is output from hall-probe, galvanicaly isolated. TMCS1101A2BQDRQ1 is the part, it works fine by hardware side. The problem what i have is mostly firmware side
2024-08-05 05:44 AM
Ok.
So need no cap here. (Or not more than 470pF , because 1nF max. load for the sensor.)
2024-08-06 04:08 AM
Thank you for all. Finally I found a way:
static void ADC_Init(void){
// Enable the ADC clock
RCC->APBENR2 |= RCC_APBENR2_ADCEN;
// Enable the ADC voltage regulator
ADC1->CR |= ADC_CR_ADVREGEN;
// Wait for the voltage regulator to stabilize
for (volatile uint32_t i = 0; i < 100000; i++);
// Calibrate the ADC
ADC1->CR |= ADC_CR_ADCAL;
while (ADC1->CR & ADC_CR_ADCAL); // Wait for calibration to complete
// Configure ADC
ADC1->CFGR1 &= ~ADC_CFGR1_RES; // 12-bit resolution
ADC1->CFGR1 |= ADC_CFGR1_CONT; // Continuous conversion mode
ADC1->CHSELR = ADC_CHSELR_CHSEL0; // Select channel 0 (PA0)
// Set sampling time to the longest possible (160.5 ADC clock cycles)
ADC1->SMPR |= ADC_SMPR_SMP2_2 | ADC_SMPR_SMP2_1 | ADC_SMPR_SMP2_0;
// Enable ADC
ADC1->CR |= ADC_CR_ADEN;
while (!(ADC1->ISR & ADC_ISR_ADRDY)); // Wait until ADC is ready
}
int main(void){
...
ADC_Init();
ADC1->CR |= ADC_CR_ADSTART;
...
}
and when I need I use:
value = ADC1->DR;