//currently 8 leds controllable
#define LED1 A0
#define LED2 A1
#define LED3 A2
#define LED4 A3
#define LED5 A4
#define LED6 A5
#define LED7 7   //A6, and A7 are ADC only. No GPIO.
#define LED8 8

#define Sensor A6

uint16_t gasVAL;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);

pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);
pinMode(LED4, OUTPUT);
pinMode(LED5, OUTPUT);
pinMode(LED6, OUTPUT);
pinMode(LED7, OUTPUT);
pinMode(LED8, OUTPUT);


Startup();

}

void loop() {
  // put your main code here, to run repeatedly:

gasVAL = analogRead(Sensor);
Serial.println(gasVAL);
lightLED(gasVAL);
delay(30);

}

void Startup (void){

digitalWrite(LED1,HIGH);
digitalWrite(LED2,HIGH);
digitalWrite(LED3,HIGH);
digitalWrite(LED4,HIGH);

delay(1000);
digitalWrite(LED1,LOW);
digitalWrite(LED2,LOW);
digitalWrite(LED3,LOW);
digitalWrite(LED4,LOW);

digitalWrite(LED5,HIGH);
digitalWrite(LED6,HIGH);
digitalWrite(LED7,HIGH);
digitalWrite(LED8,HIGH);

delay(1000);
digitalWrite(LED5,LOW);
digitalWrite(LED6,LOW);
digitalWrite(LED7,LOW);
digitalWrite(LED8,LOW);


}

void lightLED( uint16_t reading){

if (reading >= 750){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,HIGH);
  digitalWrite(LED5,HIGH);
  digitalWrite(LED6,HIGH);
  digitalWrite(LED7,HIGH);
  digitalWrite(LED8,HIGH);
}
else if (reading >= 700){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,HIGH);
  digitalWrite(LED5,HIGH);
  digitalWrite(LED6,HIGH);
  digitalWrite(LED7,HIGH);
  digitalWrite(LED8,LOW);
}
else if (reading >= 650){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,HIGH);
  digitalWrite(LED5,HIGH);
  digitalWrite(LED6,HIGH);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else if (reading >= 600){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,HIGH);
  digitalWrite(LED5,HIGH);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else if (reading >= 550){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,HIGH);
  digitalWrite(LED5,LOW);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else if (reading >= 500){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,LOW);
  digitalWrite(LED5,LOW);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else if (reading >= 450){ 
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,HIGH);
  digitalWrite(LED3,LOW);
  digitalWrite(LED4,LOW);
  digitalWrite(LED5,LOW);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else if (reading >= 400){
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,LOW);
  digitalWrite(LED3,LOW);
  digitalWrite(LED4,LOW);
  digitalWrite(LED5,LOW);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,LOW);
  digitalWrite(LED8,LOW);
}
else {
  digitalWrite(LED1,HIGH);
  digitalWrite(LED2,LOW);
  digitalWrite(LED3,HIGH);
  digitalWrite(LED4,LOW);
  digitalWrite(LED5,HIGH);
  digitalWrite(LED6,LOW);
  digitalWrite(LED7,HIGH);
  digitalWrite(LED8,LOW);
}
  
 
  
}