/* How to use a Force sensitive resistor to fade an LED with Arduino
   More info: http://www.ardumotive.com/how-to-use-a-force-sensitive-resistor-en.html
   Dev: Michalis Vasilakis // Date: 22/9/2015 // www.ardumotive.com  */
#include <SoftwareSerial.h>
//Constants:
const int ledPin = 3;     //pin 3 has PWM funtion
const int sensorPin = 4;  //pin 4 to read analog input

SoftwareSerial mySerial(ledPin, sensorPin);

//Variables:
int value = 100; //save analog value
int t_ON;
int t_OFF;

void setup() {
  pinMode(4, INPUT);
  pinMode(ledPin, OUTPUT);  //Set pin 3 as 'output'
  mySerial.begin(9600);
}

void loop() {
  int pressureSensor = analogRead(2); // Set sensorPin to analog
  t_ON = map(pressureSensor, 0, 1023, 0, 10);
  t_OFF = 10 - t_ON;
  digitalWrite(3, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(t_ON);                       // wait for a second
  digitalWrite(3, LOW);    // turn the LED off by making the voltage LOW
  delay(t_OFF);                            //Small delay
  mySerial.write((byte)sensorPin);
  //delay(100);
}