#include<stdio.h>
#include<termios.h>
#include<string.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
#include<stdlib.h>
#include<stdint.h>
int set_uart(int fd,int speed,int bits,char check,int stop)
{
	struct termios newtio,oldio;
	if(tcgetattr(fd,&oldio)!=0)
	{
          printf("tcgetattr oldio error\n");
	  return -1;
	}
	bzero(&newtio,sizeof(newtio));

	newtio.c_cflag |= CLOCAL | CREAD ;
	newtio.c_cflag &= ~CSIZE;

	switch(bits)
	{
		case 7:
			newtio.c_cflag |= CS7;
			break;
		case 8:
			newtio.c_cflag |=CS8;
			break;
	}
       
	switch(check)
	{
		case 'O':
		    newtio.c_cflag |= PARENB;
	            newtio.c_cflag |= PARODD;
		    newtio.c_iflag |= (INPCK|ISTRIP);
		    break;
		case 'E':
                    newtio.c_cflag |= PARENB;
                    newtio.c_cflag |=~PARODD;
                    newtio.c_iflag |= (INPCK|ISTRIP);
                    break;
		case 'N':
		 newtio.c_cflag &= ~PARENB;
	         break;
 
	}

	switch(speed)
	{
		case 9600:
			cfsetispeed(&newtio,B9600);
			cfsetospeed(&newtio,B9600);
			break;
		case 115200:
			cfsetispeed(&newtio,B115200);
			cfsetospeed(&newtio,B115200);
			break;
	}

	switch(stop)
        {
                case 1:
                        newtio.c_cflag &= ~CSTOPB;
                        break;
                case 2:
                        newtio.c_cflag |=CSTOPB;
                        break;
        }

	tcflush(fd,TCIFLUSH);

	if(tcsetattr(fd,TCSANOW,&newtio)!=0)
	{
		printf("tcsetattr newtio error\n");
		return -2;
	}	

	return 0;


}	

uint16_t CRC16_Modbus(uint8_t *data, uint8_t length) {
   uint16_t crc = 0xFFFF; // 初始化CRC寄存器

   for (uint8_t i = 0; i < length; i++) {
       crc ^= data[i]; // 与当前字节异或
       for (uint8_t j = 0; j < 8; j++) { // 处理每一位
           if (crc & 0x0001) {
               crc = (crc >> 1) ^ 0xA001; // 异或多项式
           } else {
               crc >>= 1;
           }
       }
   }
   // 高低字节交换
   return (crc >> 8) | (crc << 8);
}

int main(int argc,char *argv[])
{
     int fd;
     unsigned char buf[128];
     int count;
     fd= open("/dev/ttyS7",O_RDWR |O_NOCTTY | O_NDELAY);
     if(fd < 0)
     {
        printf("open ttyS7 error\n");
	return -1;
     }
/*
     fd= open("/dev/ttyS9",O_RDWR |O_NOCTTY | O_NDELAY);
     if(fd < 0)
     {
        printf("open ttyS9 error\n");
        return -1;
     }
*/
     set_uart(fd,9600,8,'N',1);
// 定义要发送的十六进制数据：01 03 02 01 00 01 D4 72
    unsigned char send_data[] = {0x01, 0x03, 0x02, 0x01, 0x00, 0x01, 0xD4, 0x72};

  uint16_t crc_data=  CRC16_Modbus(send_data, 6);
   printf("读取到 %X 字节响应数据：\n", crc_data);
    int send_len = sizeof(send_data); // 获取数据长度（8字节）
    // 发送数据
    ssize_t write_ret = write(fd, send_data, send_len);
    if (write_ret < 0)
    {
        perror("write serial port error");
        close(fd);
        return -1;
    }
    printf("成功发送 %zd 字节数据：", write_ret);
    for (int i = 0; i < send_len; i++)
    {
        printf("%02X ", send_data[i]);
    }
    printf("\n");
				      
     //write(fd,argv[1],strlen(argv[1]));
     sleep(1);
     count=read(fd,buf,sizeof(buf));
    if (count < 0)
    {
        perror("read serial port error");
    }
    else if (count == 0)
    {
        printf("未读取到响应数据\n");
    }
    else
    {
        printf("读取到 %d 字节响应数据：", count);
        for (int i = 0; i < count; i++)
        {
            printf("%02X ", buf[i]); // 十六进制格式打印响应
        }
        printf("\n");
    } 
    close(fd);
	return 0;

}