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#include <stdio.h>
#include <fcntl.h> /* File Control Definitions */
#include <termios.h> /* POSIX Terminal Control Definitions */
#include <unistd.h> /* UNIX Standard Definitions */
#include <errno.h> /* ERROR Number Definitions */
#include <sys/ioctl.h>
int main()
{
int fd;/*File Descriptor*/
printf("\n +----------------------------------+");
printf("\n | Serial Port Read |");
printf("\n +----------------------------------+");
/*------------------------------- Opening the Serial Port -------------------------------*/
/* Change /dev/ttyAMA0 to the one corresponding to your system */
fd = open("/dev/ttyAMA0",O_RDWR | O_NOCTTY | O_NDELAY | O_SYNC | O_NONBLOCK); /* ttyUSB0 is the FT232 based USB2SERIAL Converter */
/* O_RDWR - Read/Write access to serial port */
/* O_NOCTTY - No terminal will control the process */
/* Open in blocking mode,read will wait */
if(fd == -1) /* Error Checking */
printf("\n Error! in Opening ttyAMA0 ");
else
printf("\n ttyAMA0 Opened Successfully ");
/*---------- Setting the Attributes of the serial port using termios structure --------- */
struct termios SerialPortSettings; /* Create the structure */
tcgetattr(fd, &SerialPortSettings); /* Get the current attributes of the Serial port */
/* Setting the Baud rate */
cfsetispeed(&SerialPortSettings,B115200); /* Set Read Speed as 9600 */
cfsetospeed(&SerialPortSettings,B115200); /* Set Write Speed as 9600 */
/* 8N1 Mode */
SerialPortSettings.c_cflag &= ~PARENB; /* Disables the Parity Enable bit(PARENB),So No Parity */
SerialPortSettings.c_cflag &= ~CSTOPB; /* CSTOPB = 2 Stop bits,here it is cleared so 1 Stop bit */
SerialPortSettings.c_cflag &= ~CSIZE; /* Clears the mask for setting the data size */
SerialPortSettings.c_cflag |= CS8; /* Set the data bits = 8 */
SerialPortSettings.c_cflag &= ~CRTSCTS; /* No Hardware flow Control */
SerialPortSettings.c_cflag |= CREAD | CLOCAL; /* Enable receiver,Ignore Modem Control lines */
SerialPortSettings.c_iflag &= ~(IXON | IXOFF | IXANY); /* Disable XON/XOFF flow control both i/p and o/p */
SerialPortSettings.c_iflag &= ~(ICANON | ECHO | ECHOE | ISIG | IEXTEN); /* Non Cannonical mode*/
SerialPortSettings.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON); // Disable any special handling of received bytes */
SerialPortSettings.c_oflag &= ~OPOST;/*No Output Processing*/
/* Setting Time outs */
SerialPortSettings.c_cc[VMIN] = 1; /* Read at least 10 characters */
SerialPortSettings.c_cc[VTIME] = 0; /* Wait indefinetly */
if((tcsetattr(fd,TCSANOW,&SerialPortSettings)) != 0) /* Set the attributes to the termios structure*/
printf("\n ERROR ! in Setting attributes");
else
printf("\n BaudRate = 115200 \n StopBits = 1 \n Parity = none\n");
/*------------------------------- Read data from serial port -----------------------------*/
tcflush(fd, TCIFLUSH); /* Discards old data in the rx buffer */
unsigned char read_buffer[256]; /* Buffer to store the data received */
unsigned char write_buffer[]= "\x84\x00\x00\x11";
int bytes_read = 0; /* Number of bytes read by the read() system call */
int i = 0;
int bytes = 0;
while (1)
{
bytes_read = read(fd,&read_buffer,256); /* Read the data */
if (bytes_read > 0)
{
printf("Read %i bytes. Received message: %s\n", bytes_read , read_buffer);
for (i=0; i<bytes_read; i++)
{
printf("%02x",read_buffer[i]);
}
printf ("\n");
}
// int bytes_written = 0 ;
// bytes_written = write(fd,write_buffer,sizeof(write_buffer)-1);
// printf("Write %i bytes written\n", bytes_written);
// sleep(1);
}
printf("\n +----------------------------------+\n\n\n");
close(fd); /* Close the serial port */
}
