Using IR Remote Control in Raspberry Pi with a sofware in C

#include <stdio.h>
#include <wiringPi.h>
#include <sys/time.h>
#include <unistd.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <stdint.h>

#define IRPIN 1  // GPIO 1 Physical 12
#define DATANBR 150.0
#define PERIOD 80 //miliseconds
#define true (1==1)
#define false NOT true
#define MAXSAMPLES 300 * 1000

char data[MAXSAMPLES];
char binary[MAXSAMPLES] = { '\0' };

//Write Data to file
void writeFile(char* data, int len) {
  FILE *fp;
  int i;
  char str[20];

  fp = fopen("/home/pi/projects/IRcode/bin/ARM/Debug/out_power_C.txt", "w");
  for (i = 0; i < len; i++) {
    sprintf(str, "%d,%d\n", i, (char)data[i]);
    fprintf(fp, "%s", str);
  }
  fclose(fp);
}

//Get data from IR receiver
int getData() {
  int i = 0;
  unsigned int startTime = millis(), t;
  while ( ((t=millis()) - startTime) < PERIOD && i < MAXSAMPLES) {
    data[i++] = (char) digitalRead(IRPIN);
  }
  //this is for pulse analysis purpose only
  //writeFile(data, i-1);
  //exit(0);
  return i - 1;
}

//Set to \0 the binary array
void resetBinary() {
  int i;
  for (i = 0; i < 1000; i++)
    binary[i] = '\0';
}

//Decode the signal from IR receiver
void decode() {
  int i,j=0;
  double rate;
	int datalen = getData();
  //printf("Data len: %d\n", datalen);
  rate = (double) datalen / PERIOD;
  int pulses[100][100];  //pulses[][0] = value , pulses[][1] = time(us)
  int stop = 0;

  if (datalen < PERIOD)
    return;

  resetBinary();

  for (i = 1; i < datalen; i++) {
      if ( (data[i] != data[i - 1]) || (i == datalen - 1) ) {
        pulses[j][0] = data[i - 1];             //value
        pulses[j++][1] = (i - stop) * 1000 / (int)rate ; //time im us
        stop = i;
      }
  }
  int pulsesCount = j - 1;

  j = 0;
  for (i = 0; i < pulsesCount; i++) {
    if (pulses[i][0] != 1)
      continue;
    if (j != 0 && pulses[i][1] > 2000)
      break;
    else if (pulses[i][1] < 1000)
      binary[j++] = '0';
    else if (pulses[i][1] >= 1000 && pulses[i][1] <= 2000)
      binary[j++] = '1';
  }
  binary[j] = '\0';
  printf("Binary: %s\n", binary);
}

//Reverse string for Binary to decimal conversion
void reverse(char* num) {
  int i, len = (int) strlen(num), j=0;
  char tmp[len + 1];

  for (i = len-1; i >= 0; i--) 
    tmp[j++] = num[i];
  
  strncpy(num, tmp, (size_t) len);
}

//Convert binary string to integer
int binaryStr2Dec(char* bin) {
  int i, ret = 0;
  reverse(bin);
  for (i = 0; i < strlen(bin); i++)
    ret += (int)(bin[i] -'0') * (int) pow(2, i);
  return ret;
}

int main(void)
{
	//Setup WiringPi and IR receiver pin
  wiringPiSetup();
	pinMode(IRPIN, INPUT);
  pullUpDnControl(IRPIN, PUD_DOWN);

	printf("Waiting for Signal\n");
  while (true)
  {
    if (digitalRead(IRPIN) == 0) {
      decode();
      printf("Code: 0x%06x\n", binaryStr2Dec(binary));
      delay(250);
    }
  }
	
  return 0;
}