目的

    專案中的模組對輸出電壓的改變來控制功率、所以考慮用stm32內部的DAC來輸出電壓作為驅動。

 原始碼

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

	DAC_Cmd(DAC_Channel_1, ENABLE);  //ʹÄÜDAC1
  
  DAC_SetChannel1Data(DAC_Align_12b_R, 0);  

}

void Dac1_Set_Vol(uint16_t vol)
{
	uint16_t temp;
	
	temp = (uint16_t) ((vol/3.3) * 4096);
	DAC_SetChannel1Data(DAC_Align_12b_R,temp);
	DAC_SoftwareTriggerCmd(DAC_Channel_1,ENABLE);
}

void DAC_OutVoltage(float valtage)
{
	uint16_t data;
	data = (uint16_t)((valtage/3.3) *4096);
	DAC_SetChannel1Data(DAC_Align_12b_R,data);
	DAC_SoftwareTriggerCmd(DAC_Channel_1,ENABLE);
}
 

在實現輸出的電壓後、用萬用表測量。輸出的電壓雖然正確。但用在模組上發現驅動能力不夠

//DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ；

正是由於DAC_OutputBuffer沒有使能！。。。。