#include <AccelStepper.h> // http://www.airspayce.com/mikem/arduino/AccelStepper/
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <PID_v1.h>
//Connections
Adafruit_SSD1306 display(128, 64, &Wire, -1);
const byte dirPin = 11;  // varaible speed stepper motor
const byte stepPin = 12;
const byte potPin = A0;  // Potentiometer input



//const bool useDeadband = true;
const int deadband = 200;
const int step_per_rev = 200;

AccelStepper stepper(AccelStepper::DRIVER, stepPin, dirPin);

int potState = 510;
float motorSpeed = 0;
float motorRPM = 0;
float maxRPM = 50;




double Setpoint ; // will be the desired value
double Input; // photo sensor
double Output ; //LED
//PID parameters
double Kp=0, Ki=10, Kd=0; 
 
//create PID instance 
PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);



void setup() {
  Serial.begin(115200);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(WHITE);

  stepper.setMaxSpeed(2000);
  stepper.setSpeed(0);

   //Hardcode the brigdness value
  Setpoint = 175;
  //Turn the PID on
  myPID.SetMode(AUTOMATIC);
  //Adjust PID values
  myPID.SetTunings(Kp, Ki, Kd);
 }

void loop() {

    //Read the value from the light sensor. Analog input : 0 to 1024. We map is to a value from 0 to 255 as it's used for our PWM function.
  Input = map(analogRead(5), 0, 1024, 0, 255);  // photo senor is set on analog pin 5
  //PID calculation
  myPID.Compute();
  //Write the output as calculated by the PID function
  analogWrite(3,Output); //LED is set to digital 3 this is a pwm pin. 


  int pot_val = analogRead(A0);

  if (pot_val != potState ) {
    potState = pot_val;
    motorRPM = map(potState, 0, 1023, 0, maxRPM); // no deadband
    motorSpeed = motorRPM * step_per_rev / 60;
    stepper.setSpeed(motorSpeed);
    
    display.clearDisplay();
    display.setCursor(0,0);
    display.print(potState);
    display.setCursor(55,0);
    display.print(motorRPM);
    display.display();

  
  }
  Serial.print(Input);
  Serial.print(" ");
  Serial.print(Output);
  Serial.print(" ");
  Serial.println(motorSpeed);
  stepper.runSpeed();
}