使用双D/A转换通道发现第二路不是高了就是低了，不准确

啊溜溜 · 发表于 2015-11-9 11:04:43

想使用mini板的两路D/A通道分别输出对应温度湿度对应的电压值
代码如下：
#include "dac.h"

void Dac1_Init(void)
{

GPIO_InitTypeDef GPIO_InitStructure;
DAC_InitTypeDef DAC_InitType;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE );

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_4) ;

DAC_InitType.DAC_Trigger=DAC_Trigger_None;

DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;
DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;
DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ;
DAC_Init(DAC_Channel_1,&DAC_InitType);

DAC_Cmd(DAC_Channel_1, ENABLE);

DAC_SetChannel1Data(DAC_Align_8b_R, 0);

}

void Dac1_Set_Vol(u8 vol)
{
float temp=vol;
temp/=50;
temp=temp*255;
DAC_SetChannel1Data(DAC_Align_8b_R,temp);
}

void Dac2_Init(void)
{

GPIO_InitTypeDef GPIO_InitStructure;
DAC_InitTypeDef DAC_InitType;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE );

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_5) ;/

DAC_InitType.DAC_Trigger=DAC_Trigger_None;

DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;
DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;
DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ;

DAC_Init(DAC_Channel_2,&DAC_InitType);

DAC_Cmd(DAC_Channel_2, ENABLE);

DAC_SetChannel2Data(DAC_Align_8b_R, 0);
}

void Dac2_Set_Vol(u8 vol)
{
float humi=vol;
humi/=50;
humi=humi*255;
DAC_SetChannel2Data(DAC_Align_8b_R,humi);
}

啊溜溜 · 发表于 2015-11-9 11:25:11

通道二这样写也不行，怎么办？
void Dac_Init_2(void)
{
   RCC->APB2ENR|=1<<2;    //使能PORTA时钟
   RCC->APB1ENR|=1<<29;   //使能DAC时钟

    GPIOA->CRL&=0XFF0FFFFF;
    GPIOA->CRL|=0X00300000;//PA5 推挽输出
    GPIOA->ODR|=0<<5;      //PA5 输出低
// DAC->CR|=0x0b<<24; //屏蔽、幅值设置
   DAC->CR|=1<<16; //使能DAC2
   DAC->CR|=1<<17; //DAC1输出缓存使能 BOFF1=1
   DAC->CR|=0<<18; //不使用触发功能 TEN1=0
   DAC->CR|=0<<19; //DAC TIM6 TRGO,不过要TEN2=1才行
   DAC->CR|=1<<22; //不使用波形发生
   DAC->CR|=0<<24; //屏蔽、幅值设置
   DAC->CR|=0<<28; //DAC2 DMA不使能
}