#include <sys/time.h>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include "gpio-event-drv.h"
#include <fcntl.h>
#include <string.h>

#define MICRO_PER_SECOND 1000000

/* Pinos GPIO */
#define TRIG 146 //Pino 27
#define ECHO 147 //Pino 29

FILE *fs_event; //Detecção do pulso
int fd_event; //Detecção do pulso
FILE *fs_trig; 	//Trigger
int fd_trig; 	//Trigger

struct timeval start;
struct timeval stop;


void wait_us(int micro){
	usleep(micro);
}

void wait_ms(int mili){
	usleep(1000*mili);
}


void config_pins(){
	/* Detecção do pulso (ECHO) */
	
	system("insmod gpio-event-drv.ko");
	if (( fs_event = fopen( "/dev/gpio-event","r")) < 0 )
    	{
        	perror( "Unable to open /dev/gpio-event" );
        	exit( 1 );
    	}
	GPIO_EventMonitor_t  monitor;

	monitor.gpio = ECHO;
    monitor.onOff = 1;
	monitor.edgeType = GPIO_EventBothEdges;
	monitor.debounceMilliSec = 0.001;
	if ( ioctl( fileno(fs_event), GPIO_EVENT_IOCTL_MONITOR_GPIO, &monitor ) != 0 )
        {
            perror( "ioctl GPIO_EVENT_IOCTL_MONITOR_GPIO failed" );
        }

	/* Controle do trigger */
	char s[50];
	sprintf(s, "echo %d > /sys/class/gpio/export", TRIG);
	system(s);
	sprintf(s, "echo out > /sys/class/gpio/gpio%d/direction",TRIG);
	system(s);
	sprintf(s, "/sys/class/gpio/gpio%d/value",TRIG);
	if ((fs_trig = fopen(s, "w")) < 0 )
    	{
        	perror( "Unable to open TRIG" );
        	exit( 1 );
    	}
	fd_trig = fileno(fs_trig);
}

int main(void)
{
	int value;	
	char eventStr[50];
	float tempo;	
	
	config_pins();
	write(fd_trig, "0", 1);
	
	wait_ms(100);
	

	printf("Monitorando...\n");
	while(1){
		
		/* TRIGGER */
		write(fd_trig, "1", 1);
		wait_us(10);
		write(fd_trig,"0",1);
		
		/* ECHO: borda de subida */
		fgets(eventStr, sizeof(eventStr),fs_event);
		if (memchr(eventStr,'F', sizeof(eventStr)))
		{
			printf("Invertido!\n");
			wait_ms(200);
			continue;
		}
		gettimeofday(&start, NULL);
		printf("%s", eventStr);
		
		/* ECHO: borda de descida */
		fgets(eventStr, sizeof(eventStr),fs_event);
		gettimeofday(&stop, NULL);
		printf("%s", eventStr);
  	 	
		
		tempo = (float)(stop.tv_sec - start.tv_sec);
		tempo += (float)(stop.tv_usec - start.tv_usec)/(float)MICRO_PER_SECOND;
	
		if (tempo > 0.020) 
			printf("Tempo: %.6fs -- Fora de alcance! \n",tempo);
		else
			printf ("Tempo: %.6fs -- Distancia: %.2fcm \n", tempo, (float)1000000*(tempo/58.0));
		wait_ms(200);
		
	}
	
}