This sensor has a usable range of about 3-55,000 lux. This covers a pretty wide range of indoor and outdoor lighting conditions:
| Illuminance | Example |
|---|---|
| 0.002 lux | Moonless clear night sky |
| 0.2 lux | Design minimum for emergency lighting (AS2293). |
| 0.27 - 1 lux | Full moon on a clear night |
| 3.4 lux | Dark limit of civil twilight under a clear sky |
| 50 lux | Family living room |
| 80 lux | Hallway/toilet |
| 100 lux | Very dark overcast day |
| 300 - 500 lux | Sunrise or sunset on a clear day. Well-lit office area. |
| 1,000 lux | Overcast day; typical TV studio lighting |
| 10,000 - 25,000 lux | Full daylight (not direct sun) |
| 32,000 - 130,000 lux | Direct sunlight |
Simple Lux Measurement:
This sensor is simple to use with a microcontroller like the Arduino. Just connect the output to an analog pin and read. The sketch below reads the raw sensor input and converts the value to Lux. Since the logarithmic part of the output range extends from approximately 0.3v to 3.3v, we use the 3.3v pin as an external voltage reference to maximize the resolution./*
Test sketch for the Adafruit Analog Light Sensor
by Bill Earl
for Adafruit Industries
Connect sensor output to Analog Pin 0
Connect 5v to VCC and GND to GND
Connect 3.3v to the AREF pin
*/
int sensorPin = A0; // select the input pin for the potentiometer
float rawRange = 1024; // 3.3v
float logRange = 5.0; // 3.3v = 10^5 lux
void setup()
{
analogReference(EXTERNAL); //
Serial.begin(9600);
Serial.println("Adafruit Analog Light Sensor Test");
}
void loop()
{
// read the raw value from the sensor:
int rawValue = analogRead(sensorPin);
Serial.print("Raw = ");
Serial.print(rawValue);
Serial.print(" - Lux = ");
Serial.println(RawToLux(rawValue));
delay(1000);
}
float RawToLux(int raw)
{
float logLux = raw * logRange / rawRange;
return pow(10, logLux);
}
Text editor powered by tinymce.
