/********************************************************
 * PID Basic Example
 * Reading analog input A1 to control analog PWM output 3
 ********************************************************/

#include <PID_v1.h>

const byte PIN_INPUT = A1;
const byte PIN_OUTPUT = 3;

//Define Variables we'll be connecting to
double Setpoint, Input, Output;

// parameters
double Kp=2, Ki=5, Kd=1;
PID myPID(Input, Output, Setpoint, Kp, Ki, Kd, DIRECT);

void setup()
{
  //initialize the variables we're linked to
  Input = analogRead(PIN_INPUT);
  Setpoint = 100;

  //turn the PID on
  myPID.SetMode(AUTOMATIC);
}

void loop()
{
  Input = analogRead(PIN_INPUT);
  myPID.Compute();
  analogWrite(PIN_OUTPUT, Output);
}