/* --- analog_Light_Sensor  Light level below threshold turns light on ----
 *
 *   Hardware Setup- a voltage divider connected to analog 5 :
 *   1) -Wire a photoresister between +5vdc and an empty row on the breadboard
 *   2) -Wire a 10k resistor between that same row on the breadboard to ground.
 *   3) -Jumper wire from that same row to the last pin on the chip (analog 5)
 *   4) -Wire an LED thru a 330 ohm resistor from digital pin 7 to gnd
 *
 *   -Note: This sketch introduces the map() function for scaling values
 *-------------------------------------------------------------------------*/

int a_in;               // create variable for storing analog readings
int sensorPin = A5;     // variable for analog pin as A5
int LEDpin = 7;         // variable for LED pin
int threshold = 150;    // LED turns on below this number

void setup() {
  pinMode(LEDpin, OUTPUT);       // Set the digital LED pin as an output
  Serial.begin(9600);
}

void loop() {
  // read sensor, store in variable, print
  a_in = analogRead(sensorPin);       // get 10 bit analog value
  a_in = map(a_in, 0, 1023, 0, 255);  // scale it to 8 bits
  Serial.println(a_in);
  if(a_in < threshold) {
       digitalWrite(LEDpin, HIGH);    // turn LED on
   } else {
       digitalWrite(LEDpin, LOW);     // turn LED off 
     }
  delay(50);                          // easier to read screen
}