|
求助，现采用STM32L051采集电压 12位ADC,启用DMA，内部参考电压1.2V 理论上可采集最小值1.2/4096=0.2mV ,但在实际测试8MV以下就检测不到了通道数据为0. 贴出代码，熟悉ADC的大神帮忙看一下，谢谢。//ADC初始化 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_SYNC_PCLK_DIV1; hadc.Init.Resolution = ADC_RESOLUTION_12B; hadc.Init.SamplingTime = ADC_SAMPLETIME_39CYCLES_5; hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_BACKWARD; hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT; hadc.Init.ContinuousConvMode = ENABLE; hadc.Init.DiscontinuousConvMode = DISABLE; hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START; hadc.Init.DMAContinuousRequests = ENABLE; hadc.Init.EOCSelection = ADC_EOC_SINGLE_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(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_4; sConfig.Rank = ADC_RANK_CHANNEL_NUMBER; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_5; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_6; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_7; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_8; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**Configure for the selected ADC regular channel to be converted. */ sConfig.Channel = ADC_CHANNEL_9; if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); } /**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(__FILE__, __LINE__); } /**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(__FILE__, __LINE__); } } //主函数 int main(void) { HAL_Init(); SystemClock_Config(); MX_GPIO_Init(); MX_DMA_Init(); MX_TIM2_Init(); MX_ADC_Init(); HAL_ADCEx_Calibration_Start(&hadc,ADC_SINGLE_ENDED);//ADC校准 HAL_ADC_Start_DMA(&hadc,ADC_Value.ADC_ConvertedValue,ADC_NUMOFCHANNEL); MX_USART2_UART_Init(); if(HAL_TIM_Base_Start_IT(&htim2) != HAL_OK) { while(1); } /* USER CODE BEGIN 2 */ MCU_CHG_Start; MCU_DSG_Start; /* USER CODE END 2 */ /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { /* USER CODE END WHILE */ HAL_Delay(100); for(uint16_t index=0; index<ADC_NUMOFCHANNEL; index++) { ADC_Value.ADC_ConvertedVoltage[index]=(uint32_t)(ADC_Value.ADC_ConvertedValueAVER[index]&0xFFF)*ADC_VCC/4096; // mv } Project_Data.NTC1Temperature = (int32_t)get_Temperature(get_Resistance(ADC_Value.ADC_ConvertedVoltage[7])); Project_Data.NTC2Temperature = (int32_t)get_Temperature(get_Resistance(ADC_Value.ADC_ConvertedVoltage[6])); Project_Data.NTC3Temperature = (int32_t)get_Temperature(get_Resistance(ADC_Value.ADC_ConvertedVoltage[5])); Project_Data.NTC4Temperature = (int32_t)get_Temperature(get_Resistance(ADC_Value.ADC_ConvertedVoltage[4])); Project_Data.Current=(ADC_Value.ADC_ConvertedVoltage[3]-ADC_Value.ADC_ConvertedVoltage[2])*1000/Current_Resistance;//MA // HAL_IWDG_Refresh(&hiwdg); /* USER CODE BEGIN 3 */ } /* USER CODE END 3 */ } //定时器0.5ms一次 void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) { ADC_Value.ADC_Filter++; for(uint8_t index=0; index<ADC_NUMOFCHANNEL; index++) { ADC_Value.ADC_ConvertedValueSum[index] += ADC_Value.ADC_ConvertedValue[index]; } if(ADC_Value.ADC_Filter>=20)//20次滤波 { ADC_Value.ADC_Filter = 0; for(uint8_t index=0; index<ADC_NUMOFCHANNEL; index++) { ADC_Value.ADC_ConvertedValueAVER[index] = ADC_Value.ADC_ConvertedValueSum[index]/20; ADC_Value.ADC_ConvertedValueSum[index] = 0; } } } |
我目前使用是stm32L031的，adc 参考电压貌似是内部 3.3v的
评分
查看全部评分
是3.3，记混了。按3.3来算1LSB=3.3/4096=0.8MV，但ADC通道采样实际还是采集不到2MV以下的电压
你看看他内部有没有可以设置参考电压的寄存器 ？
我现在使用 stm32L031xx 这个芯片，采集 adc 电压时，貌似有时不不准，也不知道是怎么回事啊 ？
外部使用 两个 47K 电阻分压，本来想使用 470K的电阻，但是每次开机采集的数据不准，所以就换成了 47K，
换成47K的电阻分压后，刚开机可以采集到准确的adc数据，但是貌似时间运行久了 就不行了，你遇到过这个情况没有啊 ？？
采集数据不准，是指采集的通道数据跳动很大还是采集的电压值和实际值偏差很大。检查通道的实际电压是否稳定，或者尝试增加采样保持时间，若是采集的数据有波动可再软件处理上增加滤波。
我已经加了软件滤波，每次采集10次，只保留中间4次的
采集的电压值说明如下：
比如我第一次采集的是 3.30v
但是时间久了后采集的是 3.322v
电压是保持不变的