Skip to Content
  1. All products
  2. 🧠 Controllers & Systems
  3. 📡 Sensors & Modules
  4. Digital LDR Photosensitive Light Sensor Module – Adjustable Light Intensity Detection Switch for Arduino, ESP32, and Automatic Lighting Systems
  5. 📡 Sensors & Modules
Pricelist: Retail Price (B2C) Pricelist
Pricelist: Retail Price (B2C) Pricelist
Digital LDR Photosensitive Light Sensor Module – Adjustable Light Intensity Detection Switch for Arduino, ESP32, and Automatic Lighting Systems

Digital LDR Photosensitive Light Sensor Module – Adjustable Light Intensity Detection Switch for Arduino, ESP32, and Automatic Lighting Systems

(0 review)
FeatureDetails
Sensor TypeLDR (Light Dependent Resistor)
Operating Voltage3.3V to 5V DC
Output TypeDigital (D0) & Analog (A0)
Comparator ICLM393 (High Stability)
SensitivityAdjustable via Onboard Potentiometer
Detection Angle~60 Degrees
Price
₹ 33.90 ₹ 33.90
(Tax included)

Barcode: 59310

Product Description The Digital LDR Photosensitive Light Sensor Module is a high-sensitivity light detection board designed to measure ambient light intensity and trigger automated systems. It features a 5mm Light Dependent Resistor (LDR) paired with a high-precision LM393 comparator IC for stable signal processing. This dual-output module provides a real-time analog signal for measuring precise brightness levels and a digital output that toggles when light crosses a user-defined threshold. It is a fundamental component for building smart street lights, solar tracking systems, and automated indoor lighting controllers. The module's integrated voltage regulation ensures it works seamlessly with 3.3V and 5V microcontrollers like Arduino, ESP32, and STM32.

Key Features

  • Dual Signal Output: Provides both Analog (AO) for precise light measurement and Digital (DO) for threshold-based switching.

  • On-board Threshold Tuning: Features a multi-turn potentiometer to set the exact light level at which the digital output triggers.

  • High-Precision Comparator: Utilizes the LM393 IC to ensure clean digital transitions and high noise immunity.

  • Visual Status Feedback: Includes a power indicator LED and a digital signal status LED for instant debugging and calibration.

  • Compact and Easy to Mount: Small PCB footprint with a dedicated M3 mounting hole for secure attachment to project chassis.


Technical Details

  • Light Sensitive Element: Uses a premium cadmium sulfide (CdS) 5mm LDR with a spectral peak similar to the human eye.

  • Comparator Circuitry: The LM393 dual comparator ensures sharp digital edges (TTL level) with a driving capability of over 15mA.

  • Operating Voltage Range: Highly versatile operation from 3.3V to 5V, allowing for direct connection to almost any development board.

  • Digital Logic State: Default state is HIGH in darkness and pulls to LOW when light exceeds the set threshold.

  • Analog Resolution: The AO pin outputs a voltage proportional to the light intensity, which can be read by a 10-bit or 12-bit ADC.

  • Ambient Light Rejection: The integrated circuitry helps filter out high-frequency flickering from some AC lighting sources.

  • Spectral Sensitivity: Optimized for the visible light spectrum (400nm to 700nm), making it ideal for day/night sensing.

  • PCB Build Quality: Professional-grade FR-4 glass epoxy board with high-quality tin-plated solder pads for durability.

  • Current Efficiency: Draws minimal power during operation, suitable for continuous environmental monitoring in IoT devices.

  • Potentiometer Precision: Features a high-quality trimmer for fine-grained sensitivity adjustments in varied lighting conditions.

  • Signal Integrity: Designed with short trace paths between the LDR and the comparator to prevent electromagnetic interference.

  • Interface Pins: Standard 4-pin breakout: VCC (+5V), GND (Ground), DO (Digital Out), and AO (Analog Out).

  • Thermal Stability: Maintained performance over an industrial temperature range of -20°C to +85°C.

  • Mounting Stability: Includes an integrated M3 screw hole for vibration-proof mounting in robotic or automotive projects.

  • Packaging Protection: Solid-state components ensure resistance to mechanical shocks and long-term environmental exposure.

Prototyping and Engineering Tips from Robogears

  • 9V Battery Use: Do not connect a 9V battery directly to the module. Always use the 5V regulated output from your Arduino. Excess voltage will destroy the LM393 comparator and the LDR.

  • 18650 Cell: A single 18650 cell (3.7V - 4.2V) is a perfect power source. To prevent light "flickering" in your code, we recommend adding a 100uF electrolytic capacitor across the VCC and GND pins.

  • IC & Capacitor Tip: For automatic AC light control, use the DO pin to drive a 5V Relay Module through a BC547 transistor. Add a 0.1uF ceramic capacitor to the AO pin if you encounter analog signal jitter caused by WiFi signals.

  • Related Products: We recommend pairing this with our 5V Relay Modules, 3mm/5mm LED Packs, and Arduino Uno R3 for smart home automation kits.

Package Includes

  • 1 x Digital LDR Photosensitive Light Sensor Module.

Disclaimer Image is for illustration purpose only 2-3 lines. The sensor is sensitive to orientation; for the best results in solar projects, ensure the LDR is facing directly toward the primary light source.