//ENME461 Lab 1, P4

// photoresistor. This is a sensor that changes resistance based on the intensity of light. 
//The resistance of a PR DECREASES!!! as the intensity of light received by it increases. 

// Create a circuit and an appropriate program that performs the following:
// • Turns an LED on when the photoresistor is covered (by hand or a piece of paper) and
// turns off the LED when the photoresistor is uncovered.
// • Turns on a separate LED when a potentiometer is turned past the halfway point and turns
// off the LED when the potentiometer is turned below the halfway point.
// • Hint: First read the digitally mapped voltage reading from the photoresistor in ambient
// lab light, similar to Project three. Then use this number to construct an if loop which
// turns an LED on if voltage falls significantly below this number.

int greenphoto = 2;
int redpot = 5;
int potentipin = A0;
int photopin = A3;

int PotiVal;
int PhotoVal;

float PRambient = 400;
float MaxPoti = 1023;

void setup() {

  pinMode(greenphoto, OUTPUT);
  pinMode(redpot, OUTPUT);

  Serial.begin(9600); //want to have serial monitor open to see PR resistance in ambient lighting

}

void loop() {
  
  PhotoVal = analogRead(photopin); //read photopin in ambient lighting, then put above 
  Serial.print("Photoresistor Value: ");  //print recorded pin to serial screen
  Serial.println(PhotoVal);
  delay(500);

//photometer green pin
  if(PhotoVal >= PRambient) {
    digitalWrite(greenphoto, HIGH);
  }
  else {
    digitalWrite(greenphoto, LOW);
  }
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

  PotiVal = analogRead(potentipin); //read potentiometer
  Serial.print("Potentiometer Value: "); //print, to find max should be 1023
  Serial.println(PotiVal);
  delay(500);

  //potentiometer Red pin
  if( PotiVal >= (0.5 * MaxPoti)) {
    digitalWrite(redpot, HIGH);
  }
  else {
      digitalWrite(redpot, LOW);
  }

}