/*
* Program uses UART1 on the BBB to read/write 8 bit data
*
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>

#define BAUD	B115200

#define UART	"/dev/ttyO1"

int main(){
	int fd,k,count;
	struct termios oldt,newt;
	char rtemp='m',txdata=0;

//Setting variables to 0
	memset(&newt,0,sizeof(newt));

	fd=open(UART,O_RDWR|O_NOCTTY);

	
	if( fd < 0 ){
		printf("--");
		perror(UART);
		return 3;
	}

	newt.c_cflag = BAUD|CS8|CLOCAL|CREAD;
	newt.c_iflag = IGNPAR;
	newt.c_oflag = 0;
	newt.c_lflag = ICANON;


	tcflush(fd,TCIFLUSH);
	if (tcsetattr(fd,TCSANOW,&newt) < 0){
		printf("cannot set device\n");
		return 4;
	}
	k=0;
	txdata='a';

	for(;;){

		write(fd,&txdata,1);
		usleep(100000);
		
		count = read(fd,&rtemp,1);

		usleep(10000);
		printf("%c : %d\n",rtemp,count);

		txdata++;
		if(txdata > 'z'){
			txdata='a';
			k++;
		}
		
		if(k>2)
			break;

	}

	if(tcsetattr(fd,TCSANOW,&oldt)<0){
		printf("can't restore old termios\n");
		return 5;
	}
close(fd);
return 0;
}