STM32：DMA数据转运+AD多通道(软件篇)
1.接线图：
PA0接电位器,PA1~PA3接三个传感器模块的AO输出。
代码总逻辑：将AD多通道代码和DMA转运部分代码结合起来，修改参数，即可完成AD+DMA转运
2.AD.c代码部分：
#include "stm32f10x.h" // Device header
uint16_t AD_Value[4];
void AD_Init(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);//将RCC开启DMA放在此处
RCC_ADCCLKConfig(RCC_PCLK2_Div6);
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);//通道选择，选择4个
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_55Cycles5);
ADC_InitTypeDef ADC_InitStructure;
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;//连续扫描
ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描模式是连续扫描，不再是只要第一个了
ADC_InitStructure.ADC_NbrOfChannel = 4;//规定有效扫描范围4
ADC_Init(ADC1, &ADC_InitStructure);
DMA_InitTypeDef DMA_InitStructure;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
//外设基地址，ADC.DR寄存器的地址，使用取地址符&，并使用指针->表示参数
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
//低十六位数据，转运半字，16位。
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
//不自增，始终转运同一位置
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)AD_Value;//存储器基地址(目的地地址)
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 4;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//循环模式
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
//不使用软件触发，使用硬件触发，触发源是ADC1
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
DMA_Cmd(DMA1_Channel1, ENABLE);
ADC_DMACmd(ADC1, ENABLE);//开启DMA触发信号
ADC_Cmd(ADC1, ENABLE);
ADC_ResetCalibration(ADC1);
while (ADC_GetResetCalibrationStatus(ADC1) == SET);
ADC_StartCalibration(ADC1);
while (ADC_GetCalibrationStatus(ADC1) == SET);
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}
3.AD.h代码部分如下：
#ifndef __AD_H
#define __AD_H
extern uint16_t AD_Value[4];
void AD_Init(void);
#endif
4.主函数代码部分如下：
#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "OLED.h"
#include "AD.h"
int main(void)
{
OLED_Init();
AD_Init();
OLED_ShowString(1, 1, "AD0:");
OLED_ShowString(2, 1, "AD1:");
OLED_ShowString(3, 1, "AD2:");
OLED_ShowString(4, 1, "AD3:");
while (1)
{
OLED_ShowNum(1, 5, AD_Value[0], 4);
OLED_ShowNum(2, 5, AD_Value[1], 4);
OLED_ShowNum(3, 5, AD_Value[2], 4);
OLED_ShowNum(4, 5, AD_Value[3], 4);
Delay_ms(100);
}
}