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Multiple channels adc wrong sequence output (stm32f3 discovery)

d4ng3r09
Associate II
Posted on September 29, 2014 at 22:34

Hi, i managed to get adc in continuous mode to work with 2 channels.The problem is when the program starts the conversion loop ,it can give me the first channel value for 2 or 4 iterations in a row then switch to the second channel value which have the same issue.To summarise ,I have this example

(Sometimes it is more and others it is less , i guess it is randomised) Timingdealy=0 ConValue=value in ch1 Timingdealy=1 ConValue=value in ch1 Timingdealy=2 ConValue=value in ch1 Timingdealy=3 ConValue=value in ch1 Timingdealy=4 ConValue=value in ch2 Timingdealy=5 ConValue=value in ch2 My goal is to end this randomised output values. Here is my code:

#include ''stm32f30x.h''
#include ''stm32f30x_adc.h''
#include ''stm32f30x_gpio.h''
#include ''stm32f30x_rcc.h''
__IO uint32_t TimingDelay = 10;
int main(void) {
ADC_InitTypeDef ADC_InitStruct;
GPIO_InitTypeDef GPIO_InitStruct;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
int test = ADC_CR_ADCAL;
TimingDelay = 10;
int ConvValue = 0;
int calibration_value;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_ADC12, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_ADCCLKConfig(RCC_ADC12PLLCLK_Div1);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_PinLockConfig(GPIOA, GPIO_Pin_0);
GPIO_PinLockConfig(GPIOA, GPIO_Pin_1);
ADC_InitStruct.ADC_ContinuousConvMode = ADC_ContinuousConvMode_Enable;
ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStruct.ADC_ExternalTrigConvEvent = ADC_ExternalTrigConvEvent_0;
ADC_InitStruct.ADC_ExternalTrigEventEdge = ADC_ExternalTrigEventEdge_None;
ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStruct.ADC_OverrunMode = DISABLE;
ADC_InitStruct.ADC_AutoInjMode = DISABLE;
ADC_InitStruct.ADC_NbrOfRegChannel = 2;
ADC_Init(ADC1,&ADC_InitStruct);
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Clock = ADC_Clock_AsynClkMode;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_CommonInitStructure.ADC_DMAMode = ADC_DMAMode_Circular t;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = 9;
ADC_CommonInit(ADC1, &ADC_CommonInitStructure);
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_1Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_1Cycles5);
ADC_VoltageRegulatorCmd(ADC1, ENABLE);
do {
TimingDelay--;
} while (TimingDelay > 0);
ADC_SelectCalibrationMode(ADC1, ADC_CalibrationMode_Single);
ADC_StartCalibration(ADC1);
while (ADC_GetCalibrationStatus(ADC1) != RESET)
;
calibration_value = ADC_GetCalibrationValue(ADC1);
ADC_RegularChannelSequencerLengthConfig(ADC1, 1);
ADC_Cmd(ADC1, ENABLE);
ADC_StartConversion(ADC1);
//while (ADC_GetStartConversionStatus(ADC1) == RESET) 
while (1) {
while (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) != RESET) {
ConvValue = ADC_GetConversionValue(ADC1);
TimingDelay++;
}
}
return (0);
}

Thank you for your interest
1 REPLY 1
Posted on September 29, 2014 at 22:50

Multiple channels, use DMA

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