lpc1788IO口模擬IIC

#ifndef __MYIIC_H_

#define __MYIIC_H_

#include "common.h"

#include "delay.h"

#include "debugserial.h"

//sda 027 scl 028

//IO方向設(shè)置

#define IIC1_SDA_IN() P0dir(27) = 0

#define IIC1_SDA_OUT() P0dir(27) = 1

//IO操作函數(shù)

#define IIC1_READ_SDA P0in(27) //輸入SDA

void my_iic_init(void); //初始化IIC的IO口

void my_iic_start(void); //發(fā)送IIC開(kāi)始信號(hào)

void my_iic_stop(void); //發(fā)送IIC停止信號(hào)

void my_iic_sendByte(u8 txd); //IIC發(fā)送一個(gè)字節(jié)

u8 my_iic_readByte(void);//IIC讀取一個(gè)字節(jié)

u8 my_iic_waitAck(void); //IIC等待ACK信號(hào)

void my_iic_ack(void); //IIC發(fā)送ACK信號(hào)

void my_iic_nAck(void); //IIC不發(fā)送ACK信號(hào)

#endif

#include "myiic.h"

//該驅(qū)動(dòng)針對(duì)模擬IIC操作

void my_iic_init(void) //初始化IIC的IO口

{

LPC_SC->PCONP|=(1<<15);

LPC_IOCON->P0_27=0x00;//選擇gpio功能,禁止遲滯 不反向 正常推挽

LPC_IOCON->P0_27|=(1<<8);//與引腳配置相關(guān) 根據(jù)實(shí)際引腳進(jìn)行修改

LPC_IOCON->P0_28=0x00;//選擇gpio功能,禁止遲滯 不反向 正常推挽

LPC_IOCON->P0_28|=(1<<8);//與引腳配置相關(guān) 根據(jù)實(shí)際引腳進(jìn)行修改

P0dir(27)=1;//scl輸出

P0dir(28)=1;//sda輸出

P0high(27)=1;//初始化都是高電平

P0high(28)=1;

}

void my_iic_start(void) //發(fā)送IIC開(kāi)始信號(hào)

{

IIC1_SDA_OUT(); //sda線輸出

P0high(27)=1; //SDA HIGH

P0high(28)=1; //SCL HIGH

DelayUs(5);

P0low(27)=1; //SDA LOW

DelayUs(5);

P0low(28)=1; //SCL LOW

}

void my_iic_stop(void) //發(fā)送IIC停止信號(hào)

{

IIC1_SDA_OUT(); //sda線輸出

P0high(28)=1; //SCL HIGH

P0low(27)=1; //SDA LOW

DelayUs(5);

P0high(27)=1; //發(fā)送I2C總線結(jié)束信號(hào) SDA HIGH

DelayUs(5);

}

void my_iic_sendByte(u8 txd) //IIC發(fā)送一個(gè)字節(jié)

{

u8 t;

IIC1_SDA_OUT();

for(t=0;t<8;t++)

{

if(((txd&0x80)>>7))

P0high(27)=1;

else

P0low(27)=1;

txd<<=1;

P0high(28)=1; //SCL HIGH

DelayUs(5);

P0low(28)=1; //SCL LOW

DelayUs(5);

}

}

u8 my_iic_readByte(void) //IIC讀取一個(gè)字節(jié)

{

unsigned char i,receive=0;

IIC1_SDA_IN();//SDA設(shè)置為輸入

for(i=0;i<8;i++)

{

receive<<=1;

P0high(28)=1; //SCL HIGH

DelayUs(5);

if(IIC1_READ_SDA)receive++;

P0low(28)=1; //SCL LOW

DelayUs(5);

}

returnreceive;

}

u8 my_iic_waitAck(void) //IIC等待ACK信號(hào)

{

u8 ucErrTime=0;

IIC1_SDA_OUT();

P0high(27)=1; //SDA HIGH

DelayUs(5);

IIC1_SDA_IN(); //SDA設(shè)置為輸入

P0high(28)=1; //SCL HIGH

DelayUs(5);

while(IIC1_READ_SDA)

{

ucErrTime++;

DelayUs(1);

if(ucErrTime>250)

{

my_iic_stop();

return1;

}

}

P0low(28)=1; //時(shí)鐘輸出 SCL LOW

DelayUs(5);

return0;

}

void my_iic_ack(void) //IIC發(fā)送ACK信號(hào)

{

IIC1_SDA_OUT();

P0low(27)=1; //SDA LOW

DelayUs(2);

P0high(28)=1; //SCL HIGH

DelayUs(5);

P0low(28)=1; //SCL LOW

DelayUs(5);

}

void my_iic_nAck(void) //IIC不發(fā)送ACK信號(hào)

{

IIC1_SDA_OUT();

P0high(27)=1; //SDA HIGH

DelayUs(2);

P0high(28)=1; //SCL HIGH

DelayUs(5);

P0low(28)=1; //SCL LOW

DelayUs(5);

}