转换代码:
注意:
这里的temp还不是DA输出电压
DA输出电压公式:volt = temp*5/255(volt为输出电压,temp为DA转换值)
void SetDAC(unsigned char temp)
{
IIC_Start();
IIC_SendByte(0x90);
IIC_WaitAck();
IIC_SendByte(0x40);
IIC_WaitAck();
IIC_SendByte(temp);
IIC_WaitAck();
IIC_Stop();
}
实验测试 :
当temp = 200
输出电压经过以上公式求得volt = 200*5/255 =3.92V
准备一个示波器,接上板子的D/A口和GND
示波器输出3.84V,大概0.1V的误差,还可以接受。
所以,想要输出多少V的电压,就根据公式逆推求temp值就可以了
全部代码:
main.c
******************************************************************************
* 文件名:DA转换
* 描 述:
* 作 者:思索与猫
* 日 期: 19/3/28
* 备 注:
*
******************************************************************************
#include<stc15f2k60s2.h>
#include<iic.h>
typedef unsigned char uchar;
typedef unsigned int uint;
uchar temp= 200;
void CloseFucker();
void main()
{
CloseFucker();
while(1)
{
SetDAC(temp); //设置输出模拟电压
}
}
void CloseFucker()
{
P2 = P2&0x1f|0xa0;
P0 = 0xaf;
P2 = P2&0x1f;
}
iic.h
#ifndef _IIC_H
#define _IIC_H
void IIC_Start(void);
void IIC_Stop(void);
bit IIC_WaitAck(void);
void IIC_SendAck(bit ackbit);
void IIC_SendByte(unsigned char byt);
unsigned char IIC_RecByte(void);
void Delay5us();
void SetDAC(unsigned char temp);
#endif
iic.c
#include <STC15F2K60S2.H>
#include <iic.h>
#include "intrins.h"
#define DELAY_TIME 5
#define SlaveAddrW 0xA0
#define SlaveAddrR 0xA1
#define IIC_Delay(DELAY_TIME) Delay5us()
sbit SDA = P2^1;
sbit SCL = P2^0;
void Delay5us() //@12.000MHz
{
unsigned char i;
_nop_();
_nop_();
i = 12;
while (--i);
}
void IIC_Start(void)
{
SDA = 1;
SCL = 1;
IIC_Delay(DELAY_TIME);
SDA = 0;
IIC_Delay(DELAY_TIME);
SCL = 0;
}
void IIC_Stop(void)
{
SDA = 0;
SCL = 1;
IIC_Delay(DELAY_TIME);
SDA = 1;
IIC_Delay(DELAY_TIME);
}
void IIC_SendAck(bit ackbit)
{
SCL = 0;
SDA = ackbit;
IIC_Delay(DELAY_TIME);
SCL = 1;
IIC_Delay(DELAY_TIME);
SCL = 0;
SDA = 1;
IIC_Delay(DELAY_TIME);
}
bit IIC_WaitAck(void)
{
bit ackbit;
SCL = 1;
IIC_Delay(DELAY_TIME);
ackbit = SDA;
SCL = 0;
IIC_Delay(DELAY_TIME);
return ackbit;
}
void IIC_SendByte(unsigned char byt)
{
unsigned char i;
for(i=0; i<8; i++)
{
SCL = 0;
IIC_Delay(DELAY_TIME);
if(byt & 0x80) SDA = 1;
else SDA = 0;
IIC_Delay(DELAY_TIME);
SCL = 1;
byt <<= 1;
IIC_Delay(DELAY_TIME);
}
SCL = 0;
}
unsigned char IIC_RecByte(void)
{
unsigned char i, da;
for(i=0; i<8; i++)
{
SCL = 1;
IIC_Delay(DELAY_TIME);
da <<= 1;
if(SDA) da |= 1;
SCL = 0;
IIC_Delay(DELAY_TIME);
}
return da;
}
void SetDAC(unsigned char temp)
{
IIC_Start();
IIC_SendByte(0x90);
IIC_WaitAck();
IIC_SendByte(0x40);
IIC_WaitAck();
IIC_SendByte(temp);
IIC_WaitAck();
IIC_Stop();
}