//read multiple analog inputs and send their pin number and their value out the serial port

#define NumSensors  2 //define creates a constant that can be used to initalize other variables, notice no = sign or ;

int led = 13;//create a variable to hold the pin number the LED is connected to
int values[NumSensors];//create an array, a list, to hold the values of each sensor
int oldValues[NumSensors];//create an array to hold the old values of each sensor


void setup(){

  for(int i = 0; i < NumSensors; i++){//initalize number of pins the sensors are connected to using a for loop
    pinMode(i, INPUT);
  }

  Serial.begin(9600);//initalize serial communication at 9600baud
  startBlink();//blink an LED at the begining of the program
}


void loop(){

  for(int i = 0; i < NumSensors; i++){//use a for loop to read thru the number of pins the sensors are connected to
    values[i] = analogRead(i);//read the sensor and store the value in the corrosponding array index
    values[i] /= 2;//divide the sensor value by 2 to get rid of flutter in the last bit of the value, this reduces the resolution, but gives a more stable reading
    if(values[i] != oldValues[i]){//compare the sensor's current value to the old value in the same index of the oldValues array, if they are not equal(!=) then....
      Serial.print(i);//send the sensor's index out the serial port
      Serial.print(" ");//send a space out the out the serial port
      Serial.print(values[i]);//send the sensor's value out the the serial port
      Serial.print("\n");//send a new line (\n) out the serial port
      oldValues[i] = values[i];//store the current sensor reading in the corrosponding index of the oldValues array
    }
  }
  delay(10);//wait 10ms
}




void startBlink(){
  pinMode(led, OUTPUT);

  for(int i = 0; i < 4; i++){
    digitalWrite(led, HIGH);
    delay(250); 
    digitalWrite(led, LOW);
    delay(250);
  }
}