Photosensitive Brightness Resistance Sensor LDR Module
= Light Intensity Detection Module for Arduino and Microcontroller Projects =
The LDR (Light Dependent Resistor) module is a sensor that detects light intensity, with resistance decreasing as light increases and vice versa . It features a photoresistor, LM393 comparator, and a potentiometer for sensitivity adjustment .
Detects light intensity variations via analog or digital output
Adjustable sensitivity through onboard potentiometer
Operating voltage: 3.3V to 5V DC
Use AO pin for variable readings and DO pin for threshold-based triggering
Avoid environments with explosive gases or liquid exposure to prevent damage
= Technical Specifications =
| Parameter | Value |
|---|
| Operating Voltage | DC 3.3V-5V |
| Output Formats | Analog (AO) and Digital (DO) |
| Comparator IC | LM393 |
| Photoresistor Model | 5516 |
| DO Output | High/Low TTL switch signal |
| AO Output | Analog voltage proportional to light |
= Pin Configuration =
| Pin | Function |
|---|
| VCC | Power supply (3.3V-5V) |
| GND | Ground |
| AO | Analog signal output |
| DO | Digital switch output |
Key Features
+Light Intensity Detection - Photoresistor varies resistance with light level
+LM393 Comparator - Provides clean digital signal with strong driving capability >15mA
+Adjustable Sensitivity - Potentiometer sets light threshold for DO trigger
+LED Indicators - Power LED and output status LED for visual feedback
== Applications ==
- Automatic light on/off systems
- Light-seeking robots and smart cars
- Ambient light detection and monitoring
- Microcontroller trigger and relay control
Simple and cost-effective light detection solution
Easy to interface with Arduino and other microcontrollers
√ Compatible with Arduino, ESP32, STM32, and Raspberry Pi
√ Mounting holes for easy installation
√ Multiple output options for flexible integration
= Troubleshooting =
Inconsistent readings:
- Adjust the potentiometer to set appropriate sensitivity threshold
- Check VCC and GND connections
- Avoid exposing the sensor to direct bright light when calibrating
No output:
- Verify voltage supply is within 3.3-5V range
- Ensure proper pin connections (VCC, GND, AO/DO)
- Clean the photoresistor surface if dirty
