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#include "stdio.h"     
#include "string.h"    
#include "unistd.h"    
#include "fcntl.h"     
#include "errno.h"     
#include "sys/types.h"
#include "sys/stat.h"
#include "stdlib.h"
#include "stdarg.h"
#include "termios.h"
#include "linux/serial.h"  
 
#define TIOCSRS485 0x542F

//variabili generali
	int i;

//indirizzi paline esadecimali
	#define indirizzi [8] {0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08}

//CARATTERI SPECIALI
	//apertura e chiusura della stringa verso palina
	#define SYNC 0x7E
	//separatore lato web
	#define separatore ;
	//apertura e chiusura stringa lato web
	#define startEnd @
	
//COMANDI
	//comando seriale polling RFID
	#define CMD1 0x01
	//comando seriale scrittura display
	#define CMD2 0x02
	//comando sblocco bicicletta
	#define CMD3 0x03
	//comando controllo caricabatteria
	#define CMD4 0x04
 
int main(void) {
    char txBuffer[10];
    char rxBuffer[10];
    int fd;
    struct termios tty_attributes;
    struct serial_rs485 rs485conf;
	pid_t pid,sid;
	char mexSeriale[66];
 
	//DEMONIZZAZIONE
	pid=fork();
	if(pid<0)
	{
		exit(EXIT_FAILURE);
	}else
		{
			if(pid>0)
			{
				exit(EXIT_SUCCESS);
			}
		}
	umask(0);
	sid=setsid();
	if(sid<0)
	{
		exit(EXIT_FAILURE);
	}	
	if((chdir("/"))<0)
	{
		exit(EXIT_FAILURE);
	}
	
	//INIZIO DEL LOOP INFINITO
	while(1)
	{
		//CICLO CHE PASSA IN RASSEGNA UNO ALLA VOLTA TUTTI I TERMINALI COLLEGATI A PARTIRE DAL 0x01 FINO AL 0x08
		for(i==0;i<=7;i++)
		{
			if ((fd = open("/dev/ttyS0",O_RDWR|O_NOCTTY|O_NONBLOCK))<0) 
			{
				fprintf (stderr,"Open error on %s\n", strerror(errno));
				exit(EXIT_FAILURE);
			}else 
				{
					//imposto il primo carattere SYNC
					mexSeriale[0]=SYNC;
					//imposto il secondo carattere con indirizzo della palina i
					mexSeriale[1]=indirizzi [i];
				}
			//contiuna da qui
		}
	}
 
		//qui
		{
			tcgetattr(fd,&tty_attributes);
			// c_cflag
			// Enable receiver
			tty_attributes.c_cflag |= CREAD;        
			// 8 data bit
			tty_attributes.c_cflag |= CS8;          
			// c_iflag
			// Ignore framing errors and parity errors. 
			tty_attributes.c_iflag |= IGNPAR;       
			// c_lflag
			// DISABLE canonical mode.
			// Disables the special characters EOF, EOL, EOL2, 
			// ERASE, KILL, LNEXT, REPRINT, STATUS, and WERASE, and buffers by lines.
			// DISABLE this: Echo input characters.
			tty_attributes.c_lflag &= ~(ICANON);     
			tty_attributes.c_lflag &= ~(ECHO);      
			// DISABLE this: If ICANON is also set, the ERASE character erases the preceding input  
			// character, and WERASE erases the preceding word.
			tty_attributes.c_lflag &= ~(ECHOE);     
			// DISABLE this: When any of the characters INTR, QUIT, SUSP, or DSUSP are received, generate the corresponding signal. 
			tty_attributes.c_lflag &= ~(ISIG);      
			// Minimum number of characters for non-canonical read.
			tty_attributes.c_cc[VMIN]=1;            
			// Timeout in deciseconds for non-canonical read.
			tty_attributes.c_cc[VTIME]=0;           
			// Set the baud rate
			cfsetospeed(&tty_attributes,B38400);     
			cfsetispeed(&tty_attributes,B38400);
			tcsetattr(fd, TCSANOW, &tty_attributes);
			// Set RS485 mode: 
			rs485conf.flags |= SER_RS485_ENABLED;
			if (ioctl (fd, TIOCSRS485, &rs485conf) < 0) 
			{
				printf("ioctl error\n");
			}
			txBuffer[0]='A';
			write(fd,txBuffer,1);
        // Read a char
        if (read(fd,&rxBuffer,1)==1)
		{
            printf("%c",rxBuffer[0]);
            printf("\n");
        }   
    }   
    close(fd);  
    return EXIT_SUCCESS;
}