LDR (or Light Dependant Resistor, or Photoresistor) is a variable resistor. Light falling on the sensor decreases its resistance.
Output: This module outputs 5v when the sensor receives no light (the circuit is open) and 0v when exposed to bright light (the circuit is closed). When connected to an input on the Arduino using the TinkerKit Shield, you can expect to read values from 0 to 1023.
Module Description: This module features a Light Dependent Resistor, a signal amplifier, the standard TinkerKit 3pin connector, a green LED that signals that the module is correctly powered and a yellow LED whose brightness changes according to the amount of lightness.
This module is a SENSOR. The connector is an OUTPUT which must be connected to one of the INPUT connectors on the TinkerKit Shield.
/*
Analog input, analog output, serial output
Reads an analog input pin, and T000090 LDR Analog Sensor
connected to I0, and uses the result to set the brightness
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
modified on Ded 2011
by Federico Vanzati
This example code is in the public domain.
*/
#include <TinkerKit.h>
// creating the object ‘button’ that belongs to the ‘TKButton’ class
// and giving the value to the desired input pin
TKLightSensor ldr(I0);
// creating the object ‘led’ that belongs to the ‘TKLed’ class
// and giving the value to the desired output pin
TKLed led(O0);
int brightnessValue = 0; // value read from the pot
void setup() {
// initialize serial communications at 9600 bps
Serial.begin(9600);
}
void loop() {
// read the analog in value:
brightnessValue = ldr.get();
// set the led brightness
led.brightness(brightnessValue);
// print the results to the serial monitor:
Serial.print("brightness = " );
Serial.println(brightnessValue);
// wait 10 milliseconds before the next loop
// for the analog-to-digital converter to settle
// after the last reading:
delay(10);
}