我所選用的芯片是STM32F030C6,採用官方STM32CubeMX配置ADC多通道時只需勾選相應的ADC通道,而對於大部分說的Rank設置是不需要的,F0默認按通道數字號配置了通道順序。
關於ADC多通道DMA配置的順序:Enable DMA時鐘 -> 配置ADC -> 配置DMA -> 開啓傳輸
1、配置ADC
ADC_ChannelConfTypeDef sConfig = {0};
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Channel1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 1, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);
hadc.Instance = ADC1;
hadc.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV4;
hadc.Init.Resolution = ADC_RESOLUTION_12B;
hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
hadc.Init.EOCSelection = ADC_EOC_SEQ_CONV;
hadc.Init.LowPowerAutoWait = DISABLE;
hadc.Init.LowPowerAutoPowerOff = DISABLE;
hadc.Init.ContinuousConvMode = ENABLE;
hadc.Init.DiscontinuousConvMode = DISABLE;
hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc.Init.DMAContinuousRequests = ENABLE;
hadc.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
if (HAL_ADC_Init(&hadc) != HAL_OK)
{
Error_Handler();
}
sConfig.Channel = ADC_CHANNEL_2;
sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
sConfig.SamplingTime = ADC_SAMPLETIME_55CYCLES_5;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}
sConfig.Channel = ADC_CHANNEL_7;
if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
{
Error_Handler();
}
2、配置DMA,關聯ADC
void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(adcHandle->Instance==ADC1)
{
__HAL_RCC_ADC1_CLK_ENABLE();
/**ADC GPIO Configuration
PA2 ------> ADC_IN2
PA7 ------> ADC_IN7
*/
GPIO_InitStruct.Pin = Charger_detect_Pin|Current_detect_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
hdma_adc.Instance = DMA1_Channel1;
hdma_adc.Init.Direction = DMA_PERIPH_TO_MEMORY;
hdma_adc.Init.PeriphInc = DMA_PINC_DISABLE;
hdma_adc.Init.MemInc = DMA_MINC_ENABLE;
hdma_adc.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
hdma_adc.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
hdma_adc.Init.Mode = DMA_CIRCULAR;
hdma_adc.Init.Priority = DMA_PRIORITY_MEDIUM;
if (HAL_DMA_Init(&hdma_adc) != HAL_OK)
{
Error_Handler();
}
__HAL_LINKDMA(adcHandle,DMA_Handle,hdma_adc);
}
}
3、開啓傳輸
HAL_ADC_Start_DMA(&hadc, (uint32_t *)ADC_Value, 30);
實際調試過程中主要遇到兩個問題
1、因爲我的ADC配置放在adc.c文件中,而DMA配置放在stm32f0xx_hal_msp.c中,但是DMA_HandleTypeDef hdma_adc;沒有定義成全局變量,而在stm32f0xx_it.c中有DMA中斷函數,需要用到變量hdma_adc,所以如果沒有定義成全局變量,這時中斷函數中調用的hdma_adc就會是未知的,這就導致我一開啓ADC DMA整個程序就掛掉......所以配置過程中一定要注意。
2、另一個問題就是ADC採樣數據的問題,我開啓了兩個通道,DMA緩衝區大小設置爲30,但是實際採到的數據只有前7個有數據,後面都是0,且越前面的數據越大,到後面慢慢變小。
上網查閱,找到一篇文章解釋了原因:
http://www.51hei.com/bbs/dpj-40959-1.html
將數據寬度改成半字就恢復正常了