//Pushbutton switch Parameters
int pushbutton = 2;       //pushbutton pin
int pushbutton_light = 7; //pushbutton light pin

//Potentiometer Parameters
int knobe = A2;      //knobe pin
int dimmer_led = 10; //pin of light to be dimmmed

// Light sensor Parameters
int light_sensor = 3;       // DO pin of light sensor 
int light_sensor_light = 5; //light 'controlled' by light sensor

//Ultrasound Parameters
int trigPin = 9;            // TRIG pin
int echoPin = 8;            // ECHO pin
int ultrasound_light = 4;   //Ultrasound light pin


float duration_us, distance_cm;

void setup() {
  // begin serial port
  Serial.begin (9600);

  //pushbutton switch
  pinMode(pushbutton,INPUT);
  pinMode(pushbutton_light,OUTPUT);

  //Potentiometer 
  pinMode(knobe, INPUT);
  pinMode(dimmer_led, OUTPUT);

  //LDR sensor
  pinMode(light_sensor,INPUT);  // LDR Sensor output pin connected  
  pinMode(light_sensor_light,OUTPUT); //  light sensor LED PIN

  //Ultrasound sensor
  pinMode(trigPin, OUTPUT);         // configure the trigger pin to output mode
  pinMode(echoPin, INPUT);          // configure the echo pin to input mode
  pinMode(ultrasound_light,OUTPUT); // ultrasounbd LED pin
}

void loop() {

  /* Code for digital */
  if (digitalRead(pushbutton) == 0){    //if push-button is NOT pressed, LOW signal sent 
    digitalWrite(pushbutton_light,LOW); // turn LED off
  }
  else{                                 // if push button is pressed , HIGH signal sent 
    digitalWrite(pushbutton_light,HIGH);// turn LED on
  }

  /* Code for analog */
  analogWrite(10,analogRead(A2)/4);     // Read the analog input from potentiometer
                                        // Then write that analog input to the light 
  // Why divide by 4?                                  
  // analogRead is 10-bit because Arduino ADC (Analog to Digital converter) is 10-bit value
  // analogWrite is 8-bit. The PWM (Pulse-Width Modulation) timer is a 8-bit value 

  /* Code for LDR sensor*/
  if(digitalRead(light_sensor) == 0 )     //if light_sensor_do gives a LOW signal, aka it is dark
  {  
   digitalWrite(light_sensor_light,LOW);  // turn LED ON    
  }  
  else                                    // if light_sensor_do gives a HIGH signal, aka it is bright
  {  
   digitalWrite(light_sensor_light,HIGH); // turn LED OFF  
  }  

  // generate 10-microsecond pulse to TRIG pin
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // measure duration of pulse from ECHO pin
  duration_us = pulseIn(echoPin, HIGH);

  // calculate the distance
  distance_cm = 0.017 * duration_us; //unit conversion

  if (distance_cm <= 10.0){
    digitalWrite(ultrasound_light, HIGH);
  }
  if (distance_cm > 10.0){
    digitalWrite(ultrasound_light, LOW);
  }

  // print the value to Serial Monitor
  Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(10);
}