/* --- 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 } |