lirc_led.c

/* lirc_led.c                                                                 */
/*                                                                            */
/* Dummy LIRC client to flash LED on IR signal                                */ 
/*                                                                            */
/* Author : Geert Lorang <geert |AT| lorang.be> - 2014-09-29                  */
/*                                                                            */

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/prctl.h>
#include <lirc/lirc_client.h>
#include "ad1000.h"
#include "display.h"

/* exit on signal */
volatile sig_atomic_t stop;
int setup_lirc_sock();

int main(int argc, char * argv[]) {

        /* file descriptor of lirc socket */
        int lirc_sock;
        
        /* buffer for received IR code */
        ssize_t len;
        static char buffer[PACKET_SIZE+1]="";
        static int end_len=0;
        char *end;
        
        /* vars to split up received IR code */
        int keycode, rep;
        char button[PACKET_SIZE+1];
        char remote[PACKET_SIZE+1];

        /* vars for release (_UP) key */
        char *p;
        int pos;
        
        /* Open syslog */
        openlog("lirc_led", LOG_PID|LOG_CONS, LOG_USER);
        syslog(LOG_INFO, "daemon starting up");
        
        /* Initiate LIRC socket */
        if((lirc_sock = setup_lirc_sock()) < 0) {
                syslog(LOG_ERR, "lirc_init() failed");
                exit(EXIT_FAILURE);
        }
        
        /* catch shutdown signals */
        signal(SIGABRT, init_exit);
        signal(SIGTERM, init_exit);
        prctl(PR_SET_PDEATHSIG, SIGTERM);
        
        /* Each time we receive an IR code, blink LED */
        while(stop == 0) {
                len=0;
                do
                {
                        if(strchr(buffer,'\n')==NULL) {
                                len=read(lirc_sock,buffer+end_len,PACKET_SIZE-end_len);
                        }
                        if(len==-1) {
                                if(errno==EAGAIN) break;
                                exit(EXIT_FAILURE);
                        }

                        /* Socket disconnected */
                        if(len == 0) {
                                /* Socket is disconnected, wait 1s before retrying reconnect */
                                sleep(1);

                                /* We enable LED3 (red) to indicate problem */
                                set_led(DEV_LED3, 1);

                                /* Close sock */
                                lirc_deinit();

                                /* Try to reconnect every 5 seconds */
                                while((lirc_sock = setup_lirc_sock()) < 0) {
                                        sleep(5);
                                }

                                /* Socket reconnected - Disable LED3 again */
                                set_led(DEV_LED3, 0);
                        }

                        buffer[len+end_len]=0;
                        if(sscanf(buffer,"%x %x %s %s\n",&keycode, &rep,button,remote) == 4) {

                                end=strchr(buffer,'\n')+1;
                                end_len=strlen(end);
                                memmove(buffer,end,end_len+1);

                                /* look for last position of _UP in the pressed key */
                                /* if it's after position 5 we should turn off the led, otherwise turn it on */
                                /* This is required for KEY_UP (on) vs KEY_UP_UP (off) to work properly */
                                pos = -1;
                                p = button;        
                                while( (p = strstr(p, "_UP")) != NULL ) {
                                        pos = p - button;
                                        p+=3;
                                }
        
                                if(pos > 5) {
                                        set_led(DEV_LED2, 0);
                                } else {
                                        set_led(DEV_LED2, 1);
                                }
                         }
                }
                while(len!=0);
                /* Sleep 0.1s */
                usleep(100000);
        } 
        
        syslog(LOG_INFO, "caught exit signal - shutting down");

        /* Close LIRC connection */
        lirc_deinit();

        /* Close syslog */
        closelog();
        
        exit(EXIT_SUCCESS);
}


void init_exit(int signum) {
        stop = 1;
}

int setup_lirc_sock() {

        /* file descriptor of lirc socket */
        int lirc_sock;

        /* socket flags */
        int lirc_flags;

        /* Initiate LIRC */
        if( (lirc_sock = lirc_init("lirc",1)) == -1) {
                return -1;
        }

        /* Set lirc socket to NONBLOCK */
        fcntl(lirc_sock,F_SETOWN,getpid());
        lirc_flags=fcntl(lirc_sock,F_GETFL,0);
        if(lirc_flags != -1) {
                fcntl(lirc_sock,F_SETFL,lirc_flags|O_NONBLOCK);
        }

        return lirc_sock;
}