将22章ADC实验修改为DMA模式下实现

弹痕 · 发表于 2015-4-20 15:48:22

将22章ADC实验修改为DMA模式下实现，所得数据通过串口发送到电脑上，结果老是0.
/*************************/
主函数
#include "delay.h"
#include "sys.h"
#include "usart.h"
#include "adc.h"

extern __IO uint16_t ADC_ConvertedValue;
float ADC_ConvertedValueLocal;

int main(void)
{
delay_init();
LED_Init();
uart_init(9600);
Adc_Init();
while(1)
{
ADC_ConvertedValueLocal=(float)ADC_ConvertedValue*(3.3/4096);
printf("\r\n ADC_CH1_VAL:%d \r\n",ADC_ConvertedValue);
printf("\r\n ADC_CH1_VAL:%.3f V \r\n\r\n\r\n",ADC_ConvertedValueLocal);

LED0=!LED0;
delay_ms(500);
}
}

/*************************************************/
adc.c
/********************/
#include "delay.h"
#include "usart.h"

#define ADC1_DR_Address ((u32)0x40012400+0x4c)
__IO uint16_t ADC_ConvertedValue;

void Adc_Init(void)
{
ADC_InitTypeDef ADC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_ADC1,ENABLE);
RCC_ADCCLKConfig(RCC_PCLK2_Div6);

//PA1
GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AIN;
GPIO_Init(GPIOA,& GPIO_InitStructure);

ADC_DeInit(ADC1);

ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
ADC_InitStructure.ADC_DataAlign= ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = 1;
ADC_Init(ADC1, &ADC_InitStructure);

DMA_Config();
ADC_DMACmd(ADC1,ENABLE);

ADC_Cmd(ADC1,ENABLE);

ADC_ResetCalibration(ADC1);
while(ADC_GetResetCalibrationStatus(ADC1));
ADC_StartCalibration(ADC1); //AD??×?
while(ADC_GetCalibrationStatus(ADC1));

ADC_RegularChannelConfig(ADC1,ADC_Channel_1,1,ADC_SampleTime_239Cycles5);
ADC_SoftwareStartConvCmd(ADC1,ENABLE);
}
void DMA_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;

DMA_DeInit(DMA1_Channel1);

DMA_InitStructure.DMA_PeripheralBaseAddr=ADC1_DR_Address;
DMA_InitStructure.DMA_MemoryBaseAddr=(u32)&ADC_ConvertedValue;
DMA_InitStructure.DMA_DIR=DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize=1;
DMA_InitStructure.DMA_PeripheralInc= DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc=DMA_MemoryInc_Disable;
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_M2M=DMA_M2M_Disable;
DMA_Init(DMA1_Channel1,&DMA_InitStructure);
DMA_Cmd(DMA1_Channel1,ENABLE);
}