Hi everyone, i am facing a problem where i have to read 5 or more ADC channels. Of course i want to use DMA for that, but i am having some kind of problem with it. The code seems to be working, DMA_TC interrupt is generated - i have a variable which is incremented every time DMA transfer is completed. But the result i get from ADC read are bad. Right now i am trying to read five ADC channels, PA0-PA4 , and PF4, which corresponds to the ADC1_Channel1 to ADC1_Channel5, but i am always reading bad values. I have buffer which can hold 5 values from ADC read, but i only get 3 values in my buffer instead of 5, and those are crappy.
ADC_ConvertedValue[0] = 0xF920F93; ADC_ConvertedValue [1] = 0xF910F66, ADC_ConvertedValue[2] = 0x0F10, ADC_ConvertedValue[3] and [4] shows 0x0000.
Actually all channels should read something like ADC_ConvertedValue[2]. Seems that this value is correct, all the channels should read pretty much the same value.
Could anyone help me to see what i have missed and i why do i get crappy results? The code is below.
#include "stm32f30x.h"
#define buffersize 5
/* Private variables */
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_ClocksTypeDef RCC_Struct;
/* Global Variables */
unsigned char clock; // global variable to hold clock value to know from where processor is clocked.
/* - 0x00: HSI used as system clock
* - 0x04: HSE used as system clock
* - 0x08: PLL used as system clock
*/
uint32_t ADC_ConvertedValue[buffersize];
/* Function prototypes */
void DMA_Configuration(void);
void ADC_Configuration(void);
void GPIO_Configuration(void);
void Interrupt_Configuration(void);
void DelayNop(unsigned short nopcount);
unsigned char DMA_Conversion_Counter=0;
void DMA1_Channel1_IRQHandler(void)
{
if(DMA_GetITStatus(DMA1_IT_TC1) != RESET)
{
DMA_ClearITPendingBit(DMA1_IT_TC1);
// DMA_ClearFlag(DMA1_IT_TC1); // Clear DMA transfer complete flag
DMA_Conversion_Counter++;
DMA1->IFCR |= 0x00;
}
}
int main(void)
{
/* Configure System Clock to be 48MHz*/
RCC_SYSCLKConfig(RCC_SYSCLKSource_HSI);
while(!RCC_GetFlagStatus(RCC_FLAG_HSIRDY ));
RCC_PLLCmd(DISABLE);
RCC_PLLConfig(RCC_PLLSource_HSI_Div2, RCC_PLLMul_12);
RCC_PLLCmd(ENABLE);
while(!RCC_GetFlagStatus(RCC_FLAG_PLLRDY));
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
RCC_GetClocksFreq(&RCC_Struct);
clock = RCC_GetSYSCLKSource();
/* Configure Clocks */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); // Enable clock for port A.
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE); // Enable clock for port B.
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOF, ENABLE); // Enable clock for port B.
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); // Enable TIM3 clock.
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_ADC12, ENABLE); // Enable ADC clock
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); // Enable DMA1 clock
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
ADC_DeInit(ADC1); // DeInit ADC before any configuration
/* Call all configuration functions here */
ADC_Configuration();
GPIO_Configuration();
DMA_Configuration();
Interrupt_Configuration();
DMA_Cmd(DMA1_Channel1, ENABLE);
DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE);
while(1)
{
ADC_StartConversion(ADC1); // Start conversion
DelayNop(20000); // Dumb delay
}
}
void DMA_Configuration(void)
{
// Reset DMA strctuure
DMA_DeInit(DMA1_Channel1);
/* DMA1 channel1 configuration */
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(ADC1->DR);
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADC_ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = buffersize;
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_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; // Memory to memory transfer disable
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
}
void ADC_Configuration(void)
{
// DelayNop(20000); // Dumb delay
// Configure ADC for temp sensor
ADC_InitStructure.ADC_Resolution= ADC_Resolution_12b;
ADC_InitStructure.ADC_ContinuousConvMode = ADC_ContinuousConvMode_Disable;
ADC_InitStructure.ADC_ExternalTrigConvEvent = ADC_ExternalTrigEventEdge_None;
ADC_InitStructure.ADC_ExternalTrigEventEdge = ADC_ExternalTrigInjecEventEdge_None; // This parameter is ignored if ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfRegChannel = buffersize; // This parameter is ignored if Single channel mode is selected
ADC_Init(ADC1, &ADC_InitStructure);
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_Clock = ADC_Clock_SynClkModeDiv1;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_1;
ADC_CommonInitStructure.ADC_DMAMode = ADC_DMAMode_OneShot;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = 0x00;
ADC_CommonInit(ADC1, &ADC_CommonInitStructure);
/* Configure channels */
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_61Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_61Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 3, ADC_SampleTime_61Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 4, ADC_SampleTime_61Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 5, ADC_SampleTime_61Cycles5);
// ADC_RegularChannelConfig(ADC1, ADC_Channel_7, 6, ADC_SampleTime_61Cycles5);
// ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 7, ADC_SampleTime_61Cycles5);
ADC_DMACmd(ADC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
while(!(ADC_GetFlagStatus(ADC1, ADC_FLAG_RDY)));
}
void Interrupt_Configuration(void)
{
/* Configure NVIC for DMA1 channel */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); // 1 bit for preemtion, 3 bits for subpriority
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void GPIO_Configuration(void)
{
/* Pin config for ADC */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_Init(GPIOF, &GPIO_InitStructure);
// GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2;
// GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
// GPIO_Init(GPIOC, &GPIO_InitStructure);
}
void DelayNop(unsigned short nopcount)
{
unsigned short a = nopcount;
while(a--) asm("nop");
}