__IO uint16_t ADC_ConvertedValue; void ADC1_CH6_DMA_Config(void) { ADC_InitTypeDef ADC_InitStructure; ADC_CommonInitTypeDef ADC_CommonInitStructure; DMA_InitTypeDef DMA_InitStructure; GPIO_InitTypeDef GPIO_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOA, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE); DMA_DeInit(DMA2_Stream0); DMA_InitStructure.DMA_Channel = DMA_Channel_0; //Ñ¡ÔñDMAͨµÀ DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_Address; //ADCµÄÊý¾Ý¼Ä´æÆ÷µØÖ· DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC_ConvertedValue; //DMA°ÑÊý¾Ý´æÈëÕâ¸öÊý×飬һ¸ö´æ·ÅADCÖµ£¬Ò»¸ö´æ·ÅζÈÖµ DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;//ÍâÉè´æ´¢µ½ÄÚ´æ DMA_InitStructure.DMA_BufferSize = 1; //DMA´æ´¢Êý¾ÝÇø´óС£¬2¸öµ¥Î» DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//ÍâÉèµØÖ·²»ÀÛ¼Ó£¬´ÓADC¹Ì¶¨µÄDR¼Ä´æÆ÷È¡Êý¾Ý²»ÐèÒªÀÛ¼ÓµØÖ· DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;//ÄÚ´æµØÖ·ÀÛ¼Ó DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//°ë×Ö DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//DMAÑ­»·Ä£Ê½ DMA_InitStructure.DMA_Priority = DMA_Priority_High; DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable; DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull; DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; DMA_Init(DMA2_Stream0, &DMA_InitStructure); DMA_Cmd(DMA2_Stream0, ENABLE); /* Configure ADC1 Channel6 pin as analog input ******************************/ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ; GPIO_Init(GPIOA, &GPIO_InitStructure); /* ADC Common Init **********************************************************/ ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent; ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2; ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled; ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles; ADC_CommonInit(&ADC_CommonInitStructure); /* ADC1 Init ****************************************************************/ ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b; ADC_InitStructure.ADC_ScanConvMode = DISABLE; ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None; ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right; ADC_InitStructure.ADC_NbrOfConversion = 1; ADC_Init(ADC1, &ADC_InitStructure); /* ADC1 regular channe6 configuration *************************************/ ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_3Cycles); /* Enable DMA request after last transfer (Single-ADC mode) */ ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE); /* Enable ADC3 DMA */ ADC_DMACmd(ADC1, ENABLE); /* Enable ADC3 */ ADC_Cmd(ADC1, ENABLE); } void ADC_Initializes(void) { ADC1_CH6_DMA_Config(); ADC_SoftwareStartConv(ADC1); }
ADC初始化时有没有进行校准。
你的ADC的参考电压是多少,是不是电压不对。