/*
 Voltaat learn (http://learn.voltaat.com/)
 Link for full tutorial:

 Tutorial: Detect darkness using the LDR resistance

 The function of this sketch is to read the values of the LDR resistance - via the input pin of the Arduino

 Connections from the Arduino to the breadboard:
 • Arduino pin GND → Breadboard ground line
 • Arduino pin 5V → Breadboard 5V line
 • Arduino pin A3 → Common pin between LDR and the 10KΩ resistor

 Connections from the LDR:
 • First pin→ Breadboard 5V line
 • Second pin→ 10KΩ resistor left pin
 • 10KΩ resistor right pin→ Breadboard ground line

*/


// Define the variable ldr to Analog Input A3.
const int ldr = A3;

// Define ldrStatus variable
int ldrStatus;

// Commands inside void setup run once.
void setup()
{

 // ldr is defined as an input
 pinMode(ldr, INPUT);

 // Start the serial monitor at 9600 baud rate (9600 bits per second)
 Serial.begin(9600);


}

// Commands inside void loop run forever
void loop()
{
 // Read the value of analog input from LDR and assign it in the variable ldrStatus
 ldrStatus = analogRead(ldr);

 // This value can change depending on the intensity of the surrounding light and the sensitivity of the LDR
 if (ldrStatus <= 450)
 {

   // print "It is dark here " to the serial monitor at the same line
   Serial.print("It is dark here ");

   // print The ldrStatus value to the serial monitor at a new line
   Serial.println(ldrStatus);


 }
 else
 {

   // print "The light has returned " to the serial monitor at the same line
   Serial.print("The light has returned ");

   // print The ldrStatus value to the serial monitor at a new line
   Serial.println(ldrStatus);

 }

}