MSP430F5324控制AD5410输出0-20ma电流环控制电路
这是最近烟尘一个项目需要使用4路0-20ma电流输出,一开始使用的是XTR115来做,源是PWM波,但是后来发现XTR115供电是个问题,最重要的是精度无法保证,而且电流输出控制比较复杂,不是简单输入输出的。这里贴出原理图以及AD5410的接口源码。
一开始调试时发现老调不通,仔细看代码,发现自己手贱,很多写法类似的程序我都是复制过来再修改,没有详细检查,到头来,调试时才反过来查看。
#include "msp430f5324.h"
#include "AP_main.h"
#include "Timer1_A1.h"
#include "intrinsics.h"
#include "rtc.h"
#include <string.h>
#include "crc16.h"
#include "rain.h"
#include "flash.h"
#include "AD.h"
#include "AD5410.h"
void AD5410_Init(void)
{
CONFIG_AD5410_PORT;
}
unsigned char AD5410_Write_Bytes(unsigned char *ptr,unsigned char chipNum)
{
unsigned char mDat;
unsigned char mchipNum=0;
memcpy(mDat,ptr,chipNum*3);
AD5410_LATCH_L;
AD5410_SCLK_L;
while(mchipNum<chipNum)
{
for(int mPos=0;mPos<3;mPos++)
for(int mNum=0;mNum<8;mNum++)
{
AD5410_SCLK_L;
if((mDat&0x80)==0x80)
AD5410_SDI_H;
else
AD5410_SDI_L;
AD5410_SCLK_H;
AD5410_SCLK_L;
mDat<<=1;
}
mchipNum++;
}
AD5410_LATCH_L;
AD5410_LATCH_H;
AD5410_LATCH_L;
return 1;
}
unsigned char AD5410_Reset(unsigned char chipNum)
{
unsigned char mDat;
//unsigned char mchipNum=0;
mDat=0x01;mDat=0x00;mDat=AD5410_RST_REG;
for(int i=0;i<5;i++)
memcpy(mDat+3+i*3,mDat+i*3,3);
AD5410_Write_Bytes(mDat,chipNum);
return 1;
}
unsigned char AD5410_Write_ControlREG(unsigned char chipNum)
{
unsigned char mDat;
mDat=AD5410_DCEN+AD5410_R;mDat=AD5410_OUTEN;mDat=AD5410_CTR_REG;
for(int i=0;i<5;i++)
memcpy(mDat+3+i*3,mDat+i*3,3);
AD5410_Write_Bytes(mDat,chipNum);
return 1;
}
unsigned char AD5410_Write_DataREG(unsigned int *dat,unsigned char chipNum)
{
unsigned char mDat;
for(int i=0;i<chipNum;i++)
{
mDat=(unsigned char)(dat<<4);
mDat=(unsigned char)(dat>>4);
mDat=AD5410_DATA_REG;
}
AD5410_Write_Bytes(mDat,chipNum);
return 1;
}
unsigned char AD5410_Current_Output(float *currentArray,unsigned char chipNum)
{
unsigned int currentDat;
for(int i=0;i<chipNum;i++)
{
currentArray=(currentArray-4)*4096/16;
unsigned int mC=(unsigned int)currentArray*10;
if((mC%10)>=5)
currentArray=currentArray+1;
currentDat=(unsigned int)currentArray;
}
AD5410_Write_DataREG(currentDat,chipNum);
return 1;
}
头文件:
#ifndef _AD5410_H
#define _AD5410_H
#define AD5410_Port_OUT P4OUT
#define AD5410_Port_DIR P4DIR
#define AD5410_LATCH_BIT BIT0
#define AD5410_SDI_BIT BIT1
#define AD5410_SCLK_BIT BIT3
#define AD5410_LATCH_H AD5410_Port_OUT|=AD5410_LATCH_BIT
#define AD5410_LATCH_L AD5410_Port_OUT&=~AD5410_LATCH_BIT
#define AD5410_SDI_H AD5410_Port_OUT|=AD5410_SDI_BIT
#define AD5410_SDI_L AD5410_Port_OUT&=~AD5410_SDI_BIT
#define AD5410_SCLK_H AD5410_Port_OUT|=AD5410_SCLK_BIT
#define AD5410_SCLK_L AD5410_Port_OUT&=~AD5410_SCLK_BIT
#define CONFIG_AD5410_PORT {AD5410_Port_DIR|=(AD5410_LATCH_BIT+AD5410_SDI_BIT+AD5410_SCLK_BIT);AD5410_LATCH_L;AD5410_SCLK_L;AD5410_SDI_H;}
#define AD5410_COMMAND_NOP 0
#define AD5410_DATA_REG 1
#define AD5410_RECALL 2
#define AD5410_CTR_REG 0x55
#define AD5410_RST_REG 0x56
#define AD5410_READ_STA_REG 0
#define AD5410_READ_DAT_REG 1
#define AD5410_READ_CTR_REG 2
#define AD5410_REXT 0x20
#define AD5410_OUTEN 0x10
#define AD5410_SR_CLOCK 0x01
#define AD5410_SR_STEP 0xC0
#define AD5410_SREN 0x10
#define AD5410_DCEN 0x08
#define AD5410_R 0x05
void AD5410_Init(void);
unsigned char AD5410_Write_Bytes(unsigned char *ptr,unsigned char chipNum);
unsigned char AD5410_Reset(unsigned char chipNum);
unsigned char AD5410_Write_ControlREG(unsigned char chipNum);
unsigned char AD5410_Write_DataREG(unsigned int *dat,unsigned char chipNum);
unsigned char AD5410_Current_Output(float *currentArray,unsigned char chipNum);
#endif
简单测试:
AD5410_Init();
AD5410_Reset(4);
NWK_DELAY(100);
AD5410_Write_ControlREG(1);
AD5410_Write_ControlREG(2);
AD5410_Write_ControlREG(3);
AD5410_Write_ControlREG(4);
NWK_DELAY(200);
unsigned int mdat={1024,2048,3072,4095};
AD5410_Write_DataREG(mdat,4);
输出8ma,12ma,16ma,20ma 芯片采用菊花链连接,芯片上电寄存器初始值时0,所以必须一个一个的开启菊花功能;
看到菊花二字,这芯片真蛋疼 修正下:
unsigned char AD5410_Current_Output(float *currentArray,unsigned char chipNum)
{
unsigned int currentDat;
for(int i=0;i<chipNum;i++)
if(currentArray<4)
{
currentArray=4;
}
for(int i=0;i<chipNum;i++)
if(currentArray>20)
{
currentArray=20;
}
for(int i=0;i<chipNum;i++)
{
currentArray=0.02+0.07*(currentArray-4)/16;
currentArray=(currentArray-4)*4096/16;
unsigned int mC=(unsigned int)currentArray*10;
if((mC%10)>=5)
currentArray=currentArray+1;
currentDat=(unsigned int)currentArray;
}
AD5410_Write_DataREG(currentDat,chipNum);
return 1;
}
学习了,虽然这个AD5410 价钱比较贵,但是看资料还是非常好用的 谢谢楼主的贡献,芯片资料看的我一头雾水。
有个小疑问:函数AD5410_Write_DataREG的mDat=(unsigned char)(dat<<4);dat应该是*dat是吧。
下面四句话
AD5410_Write_ControlREG(1);
AD5410_Write_ControlREG(2);
AD5410_Write_ControlREG(3);
AD5410_Write_ControlREG(4);
是为了您说的开启菊花功吗?
谢谢! wei4769229 发表于 2012-9-6 11:37 static/image/common/back.gif
谢谢楼主的贡献,芯片资料看的我一头雾水。
有个小疑问:函数AD5410_Write_DataREG的mDat=(unsigned ...
是的,先打开第一个芯片,然后打开第二个,依次类推。默认的上电功能是关闭这个功能的 谢谢分享,Mark一下 东西虽好,价格太高,如要求不是很高,我一般用一个运放加三极管搞定 精度要求需要达到多少呢?运放搞不定么? MARK,最近正好要用到这个
不知道这个芯片和XTR111比较那个性能好??我现在一直用的XTR111。 楼主好资料
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