LDR Module

<syntaxhighlight lang="c">

/*

 Analog input, analog output, serial output

Reads an analog input pin, and T000090 LDR Analog Sensor connected to I0, maps the result to a range from 0 to 255
and uses the result to set the pulsewidth modulation (PWM) on a T010111 LED Module connected on O0.
Also prints the results to the serial monitor.

created 29 Dec. 2008
Modified 4 Sep 2010
by Tom Igoe
modified 7 dec 2010
by Davide Gomba 

This example code is in the public domain.

*/

#define O0 11
#define O1 10
#define O2 9
#define O3 6
#define O4 5
#define O5 3
#define I0 A0
#define I1 A1
#define I2 A2
#define I3 A3
#define I4 A4
#define I5 A5

// These constants won't change. They're used to give names // to the pins used: const int analogInPin = I0; // Analog input pin that the LDR is attached to const int analogOutPin= O0; // Analog output pin that the LED is attached to

int sensorValue = 0; // value read from the pot int outputValue = 0; // value output to the PWM (analog out)

void setup() {

 // initialize serial communications at 9600 bps:
 Serial.begin(9600); 

}

void loop() {

 // read the analog in value:
 sensorValue = analogRead(analogInPin);            
 // map it to the range of the analog out:
 outputValue = map(sensorValue, 0, 1023, 0, 255);  
 // change the analog out value:
 analogWrite(analogOutPin, outputValue);           

 // print the results to the serial monitor:
 Serial.print("sensor = " );                       
 Serial.print(sensorValue);      
 Serial.print("\t output = ");      
 Serial.println(outputValue);   

 // wait 10 milliseconds before the next loop
 // for the analog-to-digital converter to settle
 // after the last reading:
 delay(10);                     

}

</syntaxhighlight>