An Arduino light sensor, also known as a photoresistor, measures the intensity of light by changing its resistance.
How it Works:
- Light Sensitivity: The photoresistor's resistance decreases as the amount of light falling on it increases.
- Voltage Divider: The sensor is typically connected in a voltage divider circuit with a fixed resistor.
- Analog Input: The Arduino reads the voltage across the photoresistor, which is proportional to the light intensity.
- Interpretation: The Arduino translates this voltage into a digital value, allowing you to measure and control light levels.
Practical Applications:
- Automatic Lighting: Control lights based on ambient light levels, turning them on at dusk and off at dawn.
- Light-Activated Alarm: Trigger an alarm when a light source is detected.
- Robotics: Use light sensors for obstacle avoidance or line-following robots.
- Plant Monitoring: Monitor light levels for optimal plant growth.
Example Code:
const int lightSensorPin = A0; // Analog input pin for the light sensor
void setup() {
Serial.begin(9600); // Start serial communication
}
void loop() {
int lightValue = analogRead(lightSensorPin); // Read the light sensor value
Serial.print("Light Value: ");
Serial.println(lightValue); // Print the light value to the serial monitor
delay(100); // Pause for 100 milliseconds
}
This code reads the analog value from the light sensor and prints it to the serial monitor. You can use this value to control other components or implement different applications.