ATMEGA16读写iic(TWI)(24c02) C语言程序.doc

ATMEGA16读写iic(24c02) C语言程序 测试通过
#include
#include "I2C.h"
#include "1602.h"
#include "delay.h"
/*通过AVR往IIC写数据，并通过串口把数据读出显示出来*/
//===============================================================

void UART_init(void) //UART初始化
{ DDRD = 0x02;
PORTD = 0x00;
UCSRA = 0x02; /*无倍速*/
UCSRB = 0x18; /*允许接收和发送*/
UCSRC = 0x06; /*8位数据,1位停止位，无校验*/
UBRRH = 0x00;
UBRRL = 12; /*9600*/
}

//===============================================================
void USART_TXD(float data) //发送采用查询方式
{
while( !(UCSRA & BIT(UDRE)) );
UDR=data;
while( !(UCSRA & BIT(TXC )) );
UCSRA|=BIT(TXC);
}

void main(void)
{
unsigned char i;
//LCD_init();
uart_init();//TART初始化
SEI(); //全局中断使能
while(1)
{/*
I2C_Write('n',0x00);
I2C_Write('c',0x01);
I2C_Write('e',0x02);
I2C_Write('p',0x03);
I2C_Write('u',0x04);
*/
i=I2C_Read(0x00);
//LCD_write_char(0,0,i);
USART_TXD(i);
i=I2C_Read(0x01);
//LCD_write_data(i);
USART_TXD(i);
i=I2C_Read(0x02);
//LCD_write_data(i);
USART_TXD(i);
i=I2C_Read(0x03);
//LCD_write_data(i);
USART_TXD(i);
i=I2C_Read(0x04);
//LCD_write_data(i);
USART_TXD(i);

}
}
/*上面上主函数部分*/
#include
#include "delay.h"
//I2C 状态定义
//MT 主方式传输 MR 主方式接受
#define START 0x08
#define RE_START 0x10
#define MT_SLA_ACK 0x18
#define MT_SLA_NOACK 0x20
#define MT_DATA_ACK 0x28
#define MT_DATA_NOACK 0x30
#define MR_SLA_ACK 0x40
#define MR_SLA_NOACK 0x48
#define MR_DATA_ACK 0x50
#define MR_DATA_NOACK 0x58
#define RD_DEVICE_ADDR 0xA1 //前4位器件固定,后三位看连线,最后1位是读写指令位
#define WD_DEVICE_ADDR 0xA0
//常用TWI操作(主模式写和读)
#define Start() (TWCR=(1<ne SetAck (TWCR|=(1<C_Read(unsigned RegAddress);
/*********************************************
I2C总线写一个字节
返回0:写成功
返回1:写失败
**********************************************/
unsigned char I2C_Write(unsigned char Wdata,unsigned char RegAddress)
{
Start(); //I2C启动
Wait();
if(TestAck()!=START)
return 1; //ACK

Write8Bit(WD_DEVICE_ADDR); //写I2C从器件地址和写方式
Wait();
if(TestAck()!=MT_SLA_ACK)
return 1; //ACK

Write8Bit(RegAddress); //写器件相应寄存器地址
Wait();
if(TestAck()!=MT_DATA_ACK)
return 1; //ACK

Write8Bit(Wdata); //写数据到器件相应寄存器
Wait();
if(TestAck()!=MT_DATA_ACK)
return 1; //ACK

Stop(); //I2C停止
delay_nms(10); //延时
return 0;
}
/*********************************************
I2C总线读一个字节
返回0:读成功
返回1:读失败
**********************************************/
unsigned char I2C_Read(unsigned RegAddress)
{
unsigned char temp;
Start();//I2C启动
Wait();
if (TestAck()!=START)
return 1; //ACK

Write8Bit(WD_DEVICE_ADDR); //写I2C从器件地址和写方式
Wait();
if (TestAck()!=MT_SLA_ACK)
return 1; //ACK

Write8Bit(RegAddress); //写器件相应寄存器地址
Wait();
if (TestAck()!=MT_DATA_ACK)
return 1;

Start(); //I2C重新启动
Wait();
if (TestAck()!=RE_START)
return 1;

Write8Bit(RD_DEVICE_ADDR); //写I2C从器件地址和读方式
Wait();
if(TestAck()!=MR_SLA_ACK)
return 1; //ACK

Twi(); //启动主I2C读方式
Wait();
if(TestAck()!=MR_DATA_NOACK)
return 1; //ACK

temp=TWDR;//读取I2C接收数据
Stop();//I2C停止
return temp;
}
/*以上是IIC.h头文件部分，需要对照技术文档好好研究*/
*--------------------------------------------------------------------
延时函数
编译器：ICC-AVR v6.31A 日期: 2005-11-24 20:29:57
目标芯片 : M16
时钟: 8.0000MHz
作者：archeng504
-----------------------------------------------------------------------*/
#ifndef __delay_h
#define __delay_h
void delay_nus(unsigned int n);
void delay_nms(unsigned int n);
void delay_1us(void);
void delay_1ms(void) ;
void delay_1us(void) //1us延时函数
{
asm("nop");
}
void delay_nus(unsigned int n) //N us延时函数
{
unsigned int i=0;
for (i=0;i