The Use of Light Sensor

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Revision as of 02:33, 5 November 2015 by 1304410487@qq.com (talk) (Experiment: Detect analog Brightness Value)
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Outline

Microduino-Light adopts photosensitive resistor. It uses a resistor that is based on semiconductor's photoelectric effect and is able to change along with the intensity of t the incident light. The photosensitive resistor is generally applied in light measurement, light control and photoelectric conversion.

Specification

  • Electrical features
    • The brighter the light is, the bigger the output voltage gets.
    • Output analog quantity
  • Tech parameter
    • Bright Resistance(10Lux): 8-20KΩ
    • Dark Resistance: 1MΩ
    • Sensitivity: Under the light of 10Lux and 100Lux, the resistance rate is (R10/R100) =0.8
  • Size
    • Size of the Board: 20mm*10mm
    • 1.27mm-pitch 4Pin interface;
  • Connection method
    • Pin Description: GND, VCC, signal and NC. It needs analog port(A0-A7)to detect.

Development

Equipment

Module Number Function
mCookie-CoreUSB 1 Core board
mCookie-Hub 1 Sensor pin board
Microduino-Light 1 Photosensitive sensor
  • Other Hardware Equipment
    • One USB cable
Module-light.jpg

Preparation

  • Setup 1:Connect Microduino-Light and the A0 analog port of the Hub.
MCookie-pir-sensor.JPG
  • Setup 2:Connect the CoreUSB, Hub and Light to the computer with a USB cable.
MCookie-Light-pc.JPG

Experiment: Detect analog Brightness Value

  • Open Arduino IDE and copy the following code into IDE.
#define  sensorPin  A0

int state;

void setup()
{
  pinMode(sensorPin, INPUT);
  Serial.begin(9600);
}
void loop()
{
  state = analogRead(sensorPin);
  Serial.print("state:");
  Serial.println(state);
  delay(100);
}
  • Select the right board from Tools→Serial Port in Arduino IDE and download the program.
    Uploadlight.JPG
Uploadlight1.JPG
  • After the download, you can open the serial monitor. The displayed value reflects the current light intensity.
Uploadlight3.JPG
  • Result

The stronger the light is, the greater the output value becomes. Therefore, you can build some projects controlled by light intensity change.

Program Debugging

  • “#define sensorPin A0”defines sensor interface.
  • Use“analogRead(sensorPin);”function to read the output analog value of the sensor and therefore, to judge light intensity change.

Application

  • Light-control street lamp

Video