Posted on June 24, 2012 at 14:58 Hello,
I'm using IAR embedded Workbench for ARM 6.30 kickstart to program a STM32F4 DISCOVERY microcontroler.
I have two problem with ADCs:
- I use two ADC channels (12 & 14) based on the same ADC (ADC2) to 8-bits digitizing two potentiometers output voltages. The trouble is, when I change the first potentiometer value, it's affects the second potentiometer digital value.
- The strangest problem: sometimes when I run my project on the STM32 with the ''Make and Restart Debugger'' button, with NO CHANGES in my code, the ADC behavior can change: instead of being digitized on 8-bit (0 to 255), potentiometers values will be digitized on 6-bits (0 to 63) or on 16-bits (0 to 65535), I can see it on the watch !! What is the problem with IAR ?
Thanks for your help ! I work on this problem for 2 weeks...
Jean
// ADC ADRESS
#define ADC_CCR_ADDRESS ((uint32_t)0x40012308)
// Table to store digitized ADC values
extern
__IO uint16_t TabADC[2];
////////////////////////////////////////////////////////////////////
//////// ADC configuration ///////////
////////////////////////////////////////////////////////////////////
void
ADC_Config(
void
)
{
// ADC initialisation
ADC_CommonInitTypeDef ADC_CommonInitStructure;
// CLOCK set for DMA2 + GPIOC2 + ADC1 + ADC2
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_ADC2, ENABLE);
// DMA2 config (direct access memory) Stream0 channel0
DMA_InitTypeDef DMA_InitStructure;
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
// USE CHANNEL 0
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&TabADC;
// Store in my table the digitized values
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC_CCR_ADDRESS;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 2;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
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);
// DMA2_Stream0 enable
// ADCs configuration: ADC Channel 12 & 14
// POT2: ADC Channel 12 -> PIN PC2
// POT3: ADC Channel 14 -> PIN PC4
GPIO_InitTypeDef GPIO_InitStructure;
// GPIOC
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
// 'ADC ''Common''
ADC_CommonInitStructure.ADC_Mode = ADC_DualMode_RegSimult;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommonInitStructure);
// Initialisation ADC ''2'' channels 12 & 14
ADC_InitStructure.ADC_Resolution = ADC_Resolution_8b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 2;
ADC_Init(ADC2, &ADC_InitStructure);
// ADC2 regular channels 12, 14
ADC_RegularChannelConfig(ADC2, ADC_Channel_12, 1, ADC_SampleTime_3Cycles);
ADC_RegularChannelConfig(ADC2, ADC_Channel_14, 2, ADC_SampleTime_3Cycles);
// Enable DMA request after last transfer (Multi-ADC mode)
ADC_MultiModeDMARequestAfterLastTransferCmd(ENABLE);
// Start ADC2
ADC_Cmd(ADC1, ENABLE);
ADC_Cmd(ADC2, ENABLE);
// Start ADC1 Software Conversion
ADC_SoftwareStartConv(ADC1);
}
#adc
