/*
  This code is to Remove ambience noise from sensor data.
  IR LED connected to Digital pin: 4
  IR diode connected to analog input:A3

  by-Abhilash Patel


  Adapted from the above Arduino Code

  On the ATTiny45 Sensor Board the

  IR LED is connected PB4 (ATTiny45 Pin 3)
  IR Diode is connected to PB3 = A3 (ATTiny45 Pin 2)

*/

#include <SoftwareSerial.h>

SoftwareSerial mySerial(2, 1); // RX, TX

int a, b, c;

void setup()
{
  mySerial.begin(4800);
  mySerial.println("Hello, world");
  mySerial.println("start sensing");

  pinMode(4, OUTPUT);
}

void loop() {

  digitalWrite(4, HIGH);   //Turning ON LED
  delayMicroseconds(500);  //wait
  a = analogRead(A3);      //take reading from photodiode(pin A3) :noise+signal
  digitalWrite(4, LOW);    //turn Off LED
  delayMicroseconds(500);  //wait
  b = analogRead(A3);      //again take reading from photodiode :noise
  c = a - b;               //taking differnce:[ (noise+signal)-(noise)] just signal

  mySerial.print(a);       //noise+signal
  mySerial.print("\t");
  mySerial.print(b);       //noise
  mySerial.print("\t");
  mySerial.println(c);     //denoised signal

}