☀️ Light Sensors - LDR and BH1750 for Solar Monitoring

Light sensors help optimize greenhouse lighting, track solar radiation, and predict plant growth rates.

🔌 LDR (Light Dependent Resistor) Wiring:

LDR Circuit (Voltage Divider):
3.3V → LDR → A0 → 10kΩ resistor → GND
    

📖 LDR Light Reading:

#define LIGHT_PIN 34

void setup() {
    Serial.begin(115200);
}

void loop() {
    int lightValue = analogRead(LIGHT_PIN);
    // Higher value = more light (dark = low, bright = high)
    
    int lux = map(lightValue, 0, 4095, 0, 1000);
    
    Serial.printf("☀️ Light intensity: %d lux\n", lux);
    
    if (lux < 100) {
        Serial.println("🌙 Very dark - Plants need supplement light");
    } else if (lux < 500) {
        Serial.println("☁️ Cloudy - Low light conditions");
    } else if (lux > 800) {
        Serial.println("☀️ Very bright - High solar radiation");
    }
    delay(60000);
}
    

📊 BH1750 Digital Light Sensor (I2C):

#include 
#include 

BH1750 lightMeter;

void setup() {
    Serial.begin(115200);
    Wire.begin();
    lightMeter.begin();
    Serial.println("Digital Light Sensor Ready");
}

void loop() {
    float lux = lightMeter.readLightLevel();
    
    Serial.printf("📊 Light intensity: %.1f lux\n", lux);
    
    // Greenhouse recommendations
    if (lux < 2000) {
        Serial.println("⚠️ Low light - Turn on grow lights");
    } else if (lux > 80000) {
        Serial.println("⚠️ Extreme brightness - Apply shade cloth");
    }
    delay(60000);
}