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linux I2C读写EEPROM

2016-04-05 20:50 441 查看
/************************************************************///文件名:app_at24c02.c//功能:测试linux下iic读写at24c02程序//使用说明: (1)//          (2)//          (3)//          (4)//作者:jammy-lee//日期:2010-02-08/************************************************************///包含头文件#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/ioctl.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <sys/select.h>#include <sys/time.h>#include <errno.h>//宏定义#define Address 0x50                  //at24c02地址#define I2C_RETRIES   0x0701#define I2C_TIMEOUT   0x0702#define I2C_SLAVE     0x0703       //IIC从器件的地址设置#define I2C_BUS_MODE   0x0780typedef unsigned char uint8;uint8 rbuf[8] = {0x00}; //读出缓存uint8 wbuf[8] = {0x01,0x05,0x06,0x04,0x01,0x01,0x03,0x0d}; //写入缓存int fd = -1;//函数声明static uint8 AT24C02_Init(void);static uint8 i2c_write(int fd, uint8 reg, uint8 val);static uint8 i2c_read(int fd, uint8 reg, uint8 *val);static uint8 printarray(uint8 Array[], uint8 Num);//at24c02初始化static uint8 AT24C02_Init(void){fd = open("/dev/i2c/0", O_RDWR);   //允许读写if(fd < 0){perror("Can't open /dev/nrf24l01 \n"); //打开iic设备文件失败exit(1);}printf("open /dev/i2c/0 success !\n");   //打开iic设备文件成功if(ioctl(fd, I2C_SLAVE, Address)<0) {    //设置iic从器件地址printf("fail to set i2c device slave address!\n");close(fd);return -1;}printf("set slave address to 0x%x success!\n", Address);if(ioctl(fd, I2C_BUS_MODE, 1)<0)     //设置iic总线模式printf("set bus mode fail!\n");elseprintf("set bus mode ok!\n");return(1);}/*uint8 AT24C02_Write(uint8 *nData, uint8 Reg, uint8 Num){write(fd, &Reg, 1);  //usleep(100);              //延时100uswrite(fd, nData, Num);usleep(1000*4);             //延时 4msreturn(1);}uint8 AT24C02_Read(uint8 nData[], uint8 Reg, uint8 Num){write(fd, &Reg, 1);usleep(100);              //延时100usread(fd, nData, Num);usleep(1000*4);             //延时 4msreturn(1);}*///at24c02写入一字节static uint8 i2c_write(int fd, uint8 reg, uint8 val){int retries;uint8 data[2];data[0] = reg;data[1] = val;for(retries=5; retries; retries--) {if(write(fd, data, 2)==2)return 0;usleep(1000*10);}return -1;}//at24c02读取一字节static uint8 i2c_read(int fd, uint8 reg, uint8 *val){int retries;for(retries=5; retries; retries--)if(write(fd, ®, 1)==1)if(read(fd, val, 1)==1)return 0;return -1;}//输出数组static uint8 printarray(uint8 Array[], uint8 Num){uint8 i;for(i=0;i<Num;i++){printf("Data [%d] is %d \n", i ,Array[i]);}return(1);}//主函数int main(int argc, char *argv[]){int i;AT24C02_Init();usleep(1000*100);for(i=0; i<sizeof(rbuf); i++)if(i2c_read(fd, i, &rbuf[i]))break;printarray(rbuf ,8);printf("Before Write Data \n");sleep(1);for(i=0; i<sizeof(rbuf); i++)if(i2c_write(fd, i, wbuf[i]))break;printarray(wbuf ,8);printf("Writing Data \n");sleep(1);for(i=0; i<sizeof(rbuf); i++)if(i2c_read(fd, i, &rbuf[i]))break;printarray(rbuf ,8);printf("After Write Data \n");close(fd);}
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