/* ADC and LEDs

Circuit connections:
Potensiometer_Terminal_1 => Gnd
Potensiometer_Wiper => A0
Potensiometer_Terminal_2 => Vcc

PIN_0 => Resistor 220Ω => LED1_Anode – LED1_Cathode = > Gnd
PIN_1 => Resistor 220Ω => LED2_Anode – LED2_Cathode = > Gnd
PIN_2 => Resistor 220Ω => LED3_Anode – LED3_Cathode = > Gnd
PIN_3 => Resistor 220Ω => LED4_Anode – LED4_Cathode = > Gnd
PIN_4 => Resistor 220Ω => LED5_Anode – LED5_Cathode = > Gnd
*/

#define LED1_pin 0  //give the name “LED1_pin” to PIN_0
#define LED2_pin 1  //give the name “LED2_pin” to PIN_1
#define LED3_pin 2  //give the name “LED3_pin” to PIN_2
#define LED4_pin 3  //give the name “LED4_pin” to PIN_3
#define LED5_pin 4  //give the name “LED5_pin” to PIN_4
#define pot_pin A0  //give the name “pot_pin” to PIN_A0
//variable to save data from ADC
int adc_value; //number range 0~1023
//variable to calculate the analog voltage

//The setup() function initializes and sets the initial values
//It will only run once after each power up or reset
void setup() {
  //Configure PIN_0, PIN_1, PIN_2, PIN_3 and  PIN_4 to behave as output
  pinMode(LED1_pin, OUTPUT);
  pinMode(LED2_pin, OUTPUT);
  pinMode(LED3_pin, OUTPUT);
  pinMode(LED4_pin, OUTPUT);
  pinMode(LED5_pin, OUTPUT);
}

//This function loops consecutively
void loop() {
  //read analog voltage and convert to number
  adc_value = analogRead(pot_pin);
  //check if voltage < 1V
  if(adc_value<204){
      //activate LED1
    digitalWrite(LED1_pin, HIGH);
      digitalWrite(LED2_pin, LOW);
      digitalWrite(LED3_pin, LOW);
      digitalWrite(LED4_pin, LOW);
      digitalWrite(LED5_pin, LOW);
  }
  //check if voltage < 2V
  else if(adc_value<408){
      //activate LED1 and LED2
    digitalWrite(LED1_pin, HIGH);
      digitalWrite(LED2_pin, HIGH);
      digitalWrite(LED3_pin, LOW);
      digitalWrite(LED4_pin, LOW);
      digitalWrite(LED5_pin, LOW);
  }
  //check if voltage < 3V
  else if (adc_value<612){
      //activate LED1, LED2 and LED3
    digitalWrite(LED1_pin, HIGH);
      digitalWrite(LED2_pin, HIGH);
      digitalWrite(LED3_pin, HIGH);
      digitalWrite(LED4_pin, LOW);
      digitalWrite(LED5_pin, LOW);
  }  
  //check if voltage < 4V
  else if(adc_value<816){
      //activate LED1, LED2, LED3 and LED4
    digitalWrite(LED1_pin, HIGH);
      digitalWrite(LED2_pin, HIGH);
      digitalWrite(LED3_pin, HIGH);
      digitalWrite(LED4_pin, HIGH);
      digitalWrite(LED5_pin, LOW);
  }
  // if voltage < 5V
  else{//if(adc_value<1023){
      //activate all LEDs
    digitalWrite(LED1_pin, HIGH);
      digitalWrite(LED2_pin, HIGH);
      digitalWrite(LED3_pin, HIGH);
      digitalWrite(LED4_pin, HIGH);
      digitalWrite(LED5_pin, HIGH);
  }
  delay(250);  //wait for 250ms
}