Question
What am I missing? ADC again...
Posted on April 27, 2013 at 13:07
Hi all,
I've the following problem. I need to measure signal on the PC.00 pin and with the code bellow it doesn't work. :( However, if I change the pin to PC.02 and Channel 12 , everything works fine and I get the proper value for voltage on the PC.02 pin. What am I missing that on PC.00 it doesn't work and od the PC.02 is everything OK? Note, I've created a new project for test and nothing else is using the PC.00 pin. The board in question is STM32F4 Discovery. Code: #include ''stm32f4xx.h'' #include ''stm32f4_discovery.h'' #define ADC_CDR_ADDRESS ((uint32_t)0x40012308) __IO uint16_t ADCTripleConvertedValueUS0[3]; uint16_t ADC_Val; //Stores the calculated ADC value double voltage1; //Used to store the actual voltage calculated by ADC for the 1st channel double voltage2; //Used to store the actual voltage calculated by ADC for the 2nd channel double voltage3; //Used to store the actual voltage calculated by ADC for the 3rd channel ADC_InitTypeDef ADC_InitStructure; ADC_CommonInitTypeDef ADC_CommonInitStructure; DMA_InitTypeDef DMA_InitStructure; GPIO_InitTypeDef GPIO_InitStructure; int main(void) { /* Enable peripheral clocks */ RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2 | RCC_APB2Periph_ADC3, ENABLE); /* Configure ADC Channel 10 pin as analog input */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //GPIO C.00 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; GPIO_Init(GPIOC, &GPIO_InitStructure); /* DMA2 Stream0 channel0 configuration */ DMA_InitStructure.DMA_Channel = DMA_Channel_0; DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC_CDR_ADDRESS; DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCTripleConvertedValueUS0; DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory; DMA_InitStructure.DMA_BufferSize = 3; DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word; DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word; DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; 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); /* DMA2_Stream0 enable */ DMA_Cmd(DMA2_Stream0, ENABLE); /******************************************************************************/ /* ADCs configuration: triple interleaved with 5cycles delay to reach 6Msps */ /******************************************************************************/ /* ADC Common configuration *************************************************/ ADC_CommonInitStructure.ADC_Mode = ADC_TripleMode_Interl; ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles; ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_2; ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2; ADC_CommonInit(&ADC_CommonInitStructure); /* ADC1 regular channel 10 configuration ************************************/ 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); ADC_RegularChannelConfig(ADC1, ADC_Channel_10, 1, ADC_SampleTime_3Cycles); /* Enable ADC1 DMA */ ADC_DMACmd(ADC1, ENABLE); /* ADC2 regular channel 10 configuration ************************************/ ADC_Init(ADC2, &ADC_InitStructure); /* ADC2 regular channel 10 configuration */ ADC_RegularChannelConfig(ADC2, ADC_Channel_10, 1, ADC_SampleTime_3Cycles); /* ADC3 regular channel 10 configuration ************************************/ ADC_Init(ADC3, &ADC_InitStructure); /* ADC3 regular channel 10 configuration *************************************/ ADC_RegularChannelConfig(ADC3, ADC_Channel_10, 1, ADC_SampleTime_3Cycles); /* Enable DMA request after last transfer (multi-ADC mode) ******************/ ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE); /* Enable ADC1 **************************************************************/ ADC_Cmd(ADC1, ENABLE); /* Enable ADC2 **************************************************************/ ADC_Cmd(ADC2, ENABLE); /* Enable ADC3 **************************************************************/ ADC_Cmd(ADC3, ENABLE); /* Start ADC1 Software Conversion */ ADC_SoftwareStartConv(ADC1); //Led Init STM_EVAL_LEDInit(LED3); STM_EVAL_LEDInit(LED4); STM_EVAL_LEDInit(LED5); STM_EVAL_LEDInit(LED6); while (1) { STM_EVAL_LEDOff(LED3); STM_EVAL_LEDOff(LED4); STM_EVAL_LEDOff(LED5); STM_EVAL_LEDOff(LED6); ADC_Val = ADCTripleConvertedValueUS0[0]; voltage1 = (3.3 * ADC_Val) / 4096; ADC_Val = ADCTripleConvertedValueUS0[1]; voltage2 = (3.3 * ADC_Val) / 4096; ADC_Val = ADCTripleConvertedValueUS0[1]; voltage3 = (3.3 * ADC_Val) / 4096; voltage1 = (voltage1 + voltage2 + voltage3)/3; if ((voltage1 >= 0) && (voltage1 < 0.2)) { STM_EVAL_LEDOn(LED3); } else if ((voltage1 >= 0.2) && (voltage1 < 0.4)) { STM_EVAL_LEDOn(LED4); } else if ((voltage1 >= 0.4) && (voltage1 < 0.5)) { STM_EVAL_LEDOn(LED5); } else {//voltage1 >= 0.5 STM_EVAL_LEDOn(LED6); } } } Thank you for your answers.