Analog light sensor outputs are strange?

hello all

ive bought light sensor module:

http://www.fasttech.com/products/0/10004903/1380700-photosensitive-diode-light-sensor-module

ive put gnd gnd, vcc 5 v on arduino , signal a1.

i have uploaded sketch it:

code: [select]


int sensorpin = a1;
int lightvalue = 0;


// light sensor
// setup routine runs once when press reset:
void setup() {
  // initialize serial communication @ 9600 bits per second:
  serial.begin(9600);
}

// loop routine runs on , on again forever:
void loop() {
  // read analog input on analog pin 2 (the light sensor):
  lightvalue = analogread(sensorpin);
  // print out value read:
  serial.print("the lightvalue ");
  serial.println(lightvalue);
  delay(500);        // delay in between reads stability
}

this results in output of 221 in serial monitor. nothing happens when put more light onto or cover up. when adjusting potentiometer on module jumps @ 1 point 249.

any ideas doing wrong?

the photo shows electronic brick 2 outputs, 1 analog, 1 digital , 4 pins.

which output pin connecting to??

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