#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/i2c-dev.h>
#include <fcntl.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int func(unsigned char byteFlag, int whichBit)
{
    if (whichBit > 0 && whichBit <= 8)
        return (byteFlag & (1<<(whichBit-1)));
    else
        return 0;
}

main()
{
 float min = 0;
 float max = 0;
 printf("Podaj minimalny zakres: ");
 scanf("%f", &min;);
 printf("Podaj maksymalny zakres: ");
 scanf("%f", &max;);
 wiringPiSetup();
 int fd;              // File descrition
 char *fileName = "/dev/i2c-1";        // Name of the port we will be using
 int  address = 0x48;          // Address of TPA81 shifted right 1 bit
 unsigned char buf[10];
 pinMode(0,OUTPUT);
 digitalWrite(0,LOW);
 if ((fd = open(fileName, O_RDWR)) < 0) {     // Open port for reading and writing
  printf("Failed to open i2c port\n");
  exit(1);
 }
 
 if (ioctl(fd, I2C_SLAVE, address) < 0) {     // Set the port options and set the address of the device we wish to speak to
  printf("Unable to get bus access to talk to slave\n");
  exit(1);
 }
 
 
 buf[0] = 0;             // This is the register we wish to read from
 
 if ((write(fd, buf, 1)) != 1) { 
  //printf("%c\n",buf);     // Send register to read from
  printf("Error writing to i2c slave\n");
  exit(1);
 }
 float temp = 0;
 for(;;)
 {
 if (read(fd, buf, 10) != 10) {        // Read back data into buf[]
  printf("Unable to read from slave\n");
  exit(1);
 }
 else {
  int znak = func(buf[0],8);
  unsigned char x;
  //printf("plus czy minus %d\n",znak);
  if(znak == 128){
   x = buf[0];
   x = x- 0x80;
   x = 127 - x;
  }
  else{
  x=buf[0];
  }
  temp =(float) buf[1]/64;
  temp = temp /4;
  temp = temp + x;
  if (znak ==0){
  printf("Temperatura to plus: %f\n",temp);
  }
  else {
  printf("Temperatura to minus: %f\n",temp);
  }
 }
  if(temp > max || temp < min){
   digitalWrite(0,HIGH);
   delay(500);
   digitalWrite(0,LOW);
   delay(500);
  }
 }
}