本文讲述基于STM32G070进行ADC多通道采集,并分别介绍非DMA方式和DMA方式。
1. 非DMA方式采集
ADC初始化代码如下(使用STM32CubeMx自动生成),配置了3个通道:
- static void MX_ADC1_Init(void)
- {
- /* USER CODE BEGIN ADC1_Init 0 */
- /* USER CODE END ADC1_Init 0 */
- ADC_ChannelConfTypeDef sConfig = {0};
- /* 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)
- */
- hadc1.Instance = ADC1;
- hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
- hadc1.Init.Resolution = ADC_RESOLUTION_12B;
- hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
- hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
- hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
- hadc1.Init.LowPowerAutoWait = DISABLE;
- hadc1.Init.LowPowerAutoPowerOff = DISABLE;
- hadc1.Init.ContinuousConvMode = DISABLE;
- hadc1.Init.NbrOfConversion = 3;
- hadc1.Init.DiscontinuousConvMode = ENABLE;
- hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
- hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
- hadc1.Init.DMAContinuousRequests = DISABLE;
- hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
- hadc1.Init.SamplingTimeCommon1 = ADC_SAMPLETIME_1CYCLE_5;
- hadc1.Init.SamplingTimeCommon2 = ADC_SAMPLETIME_1CYCLE_5;
- hadc1.Init.OversamplingMode = DISABLE;
- hadc1.Init.TriggerFrequencyMode = ADC_TRIGGER_FREQ_HIGH;
- if (HAL_ADC_Init(&hadc1) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_4;
- sConfig.Rank = ADC_REGULAR_RANK_1;
- sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_5;
- sConfig.Rank = ADC_REGULAR_RANK_2;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_9;
- sConfig.Rank = ADC_REGULAR_RANK_3;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /* USER CODE BEGIN ADC1_Init 2 */
- /* USER CODE END ADC1_Init 2 */
- }
复制代码 获取ADC数据
- // 校准
- HAL_ADCEx_Calibration_Start(&hadc1);
- for (idx = 0; idx < 3; idx++)
- {
- HAL_ADC_Start(&hadc1);
- HAL_ADC_PollForConversion(&hadc1, 50);
- /* Check if the continous conversion is finished */
- if(HAL_IS_BIT_SET(HAL_ADC_GetState(&hadc1), HAL_ADC_STATE_REG_EOC))
- {
- /* Get the converted value */
- AD_Value[idx] = HAL_ADC_GetValue(&hadc1);
- }
- }
- HAL_ADC_Stop(&hadc1);
复制代码 1.1 关于ADC扫描定序(scan sequencer)
ADC scan sequencer can be used in two different modes. 配置ADC多通道采集时,对于各个通道的采集顺序有两种方式:
Sequencer fully configurable (The order in which the channels are scanned is independent from the channel number)
采用这种方式时,ADC的通道扫描顺序将和channel number不再相关,如1中代码,就采用了这种方式
- //扫描方式:ADC_SCAN_ENABLE
- hadc1.Init.ScanConvMode = ADC_SCAN_ENABLE;
- //...
- sConfig.Channel = ADC_CHANNEL_5;
- sConfig.Rank = ADC_REGULAR_RANK_2;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- sConfig.Channel = ADC_CHANNEL_6;
- sConfig.Rank = ADC_REGULAR_RANK_1;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
复制代码 如果按照如上代码配置,在采集时,将先采集channel 6,再采集channel 5。但是使用该方式时,需要注意Only channel 0 to channel 14 can be selected in this sequence。即channel 15/16/17/18无法使用该方式,如果需要使用channel 15-18,则可以使用下面第二种扫描方式。
Sequencer not fully configurable (The order in which the channels are scanned is defined by the channel number)
这种方式比较好理解,就是按照channel number的大小,按顺序进行扫描,配置代码如下:
- // 扫描方式:ADC_SCAN_SEQ_FIXED
- hadc1.Init.ScanConvMode = ADC_SCAN_SEQ_FIXED;
- sConfig.Channel = ADC_CHANNEL_16;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
复制代码 2. DMA方式采集
直接上代码:
- static void MX_ADC1_Init(void)
- {
- /* USER CODE BEGIN ADC1_Init 0 */
- /* USER CODE END ADC1_Init 0 */
- ADC_ChannelConfTypeDef sConfig = {0};
- /* 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)
- */
- hadc1.Instance = ADC1;
- hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;
- hadc1.Init.Resolution = ADC_RESOLUTION_12B;
- hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
- hadc1.Init.ScanConvMode = ADC_SCAN_SEQ_FIXED;
- hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
- hadc1.Init.LowPowerAutoWait = DISABLE;
- hadc1.Init.LowPowerAutoPowerOff = DISABLE;
- hadc1.Init.ContinuousConvMode = ENABLE;
- hadc1.Init.DiscontinuousConvMode = DISABLE;
- hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
- hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
- hadc1.Init.DMAContinuousRequests = ENABLE;
- hadc1.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
- hadc1.Init.SamplingTimeCommon1 = ADC_SAMPLETIME_12CYCLES_5;
- hadc1.Init.OversamplingMode = DISABLE;
- hadc1.Init.TriggerFrequencyMode = ADC_TRIGGER_FREQ_HIGH;
- if (HAL_ADC_Init(&hadc1) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_4;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_5;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_9;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_10;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /** Configure Regular Channel
- */
- sConfig.Channel = ADC_CHANNEL_16;
- sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
- if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
- {
- Error_Handler();
- }
- /* USER CODE BEGIN ADC1_Init 2 */
- /* USER CODE END ADC1_Init 2 */
- }
- static void MX_DMA_Init(void)
- {
- /* DMA controller clock enable */
- __HAL_RCC_DMA1_CLK_ENABLE();
- /* DMA interrupt init */
- /* DMA1_Channel1_IRQn interrupt configuration */
- HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
- HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);
- }
- void HAL_ADC_MspInit(ADC_HandleTypeDef* hadc)
- {
- GPIO_InitTypeDef GPIO_InitStruct = {0};
- if(hadc->Instance==ADC1)
- {
- /* USER CODE BEGIN ADC1_MspInit 0 */
- /* USER CODE END ADC1_MspInit 0 */
- /* Peripheral clock enable */
- __HAL_RCC_ADC_CLK_ENABLE();
- __HAL_RCC_GPIOA_CLK_ENABLE();
- __HAL_RCC_GPIOB_CLK_ENABLE();
- /**ADC1 GPIO Configuration
- PA4 ------> ADC1_IN4
- PA5 ------> ADC1_IN5
- PB1 ------> ADC1_IN9
- PB2 ------> ADC1_IN10
- PB12 ------> ADC1_IN16
- */
- GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5;
- GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
- GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_12;
- GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
- /* ADC1 DMA Init */
- /* ADC1 Init */
- hdma_adc1.Instance = DMA1_Channel1;
- hdma_adc1.Init.Request = DMA_REQUEST_ADC1;
- hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;
- hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;
- hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;
- hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
- hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
- hdma_adc1.Init.Mode = DMA_CIRCULAR;
- hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
- if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)
- {
- Error_Handler();
- }
- __HAL_LINKDMA(hadc,DMA_Handle,hdma_adc1);
- /* USER CODE BEGIN ADC1_MspInit 1 */
- /* USER CODE END ADC1_MspInit 1 */
- }
- }
复制代码 初始化完成后,即可使用:
- //开始ADC转换
- HAL_ADCEx_Calibration_Start(&hadc1);
- HAL_ADC_Start_DMA(&hadc1, (uint32_t *)&AD_Value_Buffer, AD_DMA_BUFF_LENGTH);
复制代码 注:AD_Value_Buffer为事先定义好的数组,长度为AD_DMA_BUFF_LENGTH
接下来,无需CPU参与,DMA将会把ADC采集到数据搬运至AD_Value_Buffer的地址中,当长度达到AD_DMA_BUFF_LENGTH时,将从头开始,此时会覆盖数据。
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