[app]温度传感器测试程序
刚开始去读/dev/i2c-1, 但是在设置地址的时候,始终错误,返回-1, 所以最后还是用了sys接口
/******************************************* * Description: Read temperature sensor from LM75 * Author: Aaron.gao * Data: 20170524 * Histroy: * 1. NULL * ****************************************/ #include <stdio.h> #include <string.h> #include <unistd.h> #include <linux/i2c-dev.h> #include <stdlib.h> #include <fcntl.h> #include <termios.h> /* main func */ int main(int argc, char **argv) { int ret, fd; char buffer[10]; int value; float temp = 0.0; while(1) { /* open device */ fd = open("/sys/bus/i2c/devices/i2c-1/1-004f/hwmon/hwmon0/temp1_input", O_RDONLY); if( fd < 0) { printf("fd is %d\r\n", fd); printf("open i2c device-lm75 failed!\r\n"); exit(1); } ret = read(fd, buffer, 10); if(ret < 0) { printf("read error\r\n"); } value = atoi(buffer); memset(buffer, 0, strlen(buffer)); temp = value / 1000.0; printf("environment temperature is %.2lfC\r\n", temp); sleep(2); close(fd); } return 0; }