LM393 Photosensitive Light Sensor Module (4-Pin LDR)

The LM393 Photosensitive Light Sensor Module (4-Pin LDR) is a light-detecting board that pairs a light-dependent resistor with an LM393 voltage comparator to sense changes in ambient brightness. It outputs both a digital switching signal and an analog voltage proportional to light intensity.

Key features:

• Dual Output: Provides a digital (DO) output for simple light/dark switching and an analog (AO) output for precise brightness readings.
• Adjustable Sensitivity: An onboard potentiometer sets the light threshold at which the digital output triggers.
• LM393 Comparator: Converts the LDR’s changing resistance into a clean, stable output signal.
• Status LEDs: Power and digital-output indicator LEDs make wiring and testing straightforward.
• 4-Pin Header: Simple VCC, GND, DO, and AO pinout connects directly to any microcontroller.
• Low-Cost Automation: Ideal for automatic lighting, day/night detection, and light-following robots.

Its small size and simple interface make it a convenient building block for Arduino, ESP32, and Raspberry Pi light-sensing projects.