Raindrop Sensor HL-01 Module

The Raindrop Sensor HL-01 Module is a dual-part weather and moisture monitoring sensor designed for microcontrollers like Arduino. It comprises a physical rain-sensing pad and an electronics control module that processes the water detection signals.Key Technical Specifications

• Operating Voltage: 3.3V to 5V DC.
• Comparator Chip: Employs an LM393 wide-voltage comparator for clean waveforms and stable logic.
• Sensing Plate: Built using high-quality, dual-sided FR-04 material (5.0cm x 4.0cm) with a nickel-plated surface to fight oxidation and preserve high conductivity.
• Control Board Size: 3.2cm x 1.4cm with integrated mounting bolt holes.
• Output Current Drive: Greater than 15mA.

Output Modes & FunctionalityThe control board features two distinct output methods to fit different project requirements:

• Digital Output (DO): Delivers a TTL switch signal (0 or 1). When the pad is dry, the output stays HIGH. When a water droplet bridges the nickel traces, the output drops to LOW and illuminates an onboard switch indicator LED. You can fine-tune this exact precipitation threshold using the integrated potentiometer.
• Analog Output (AO): Continuously sends a variable voltage signal proportional to the level of moisture on the pad. Connecting this pin to a microcontroller’s Analog-to-Digital Converter (ADC) allows you to measure real-time rainfall intensity.

Pin ConfigurationThe electronic control module provides four primary pins for interfacing:

1. VCC: Connects to the 3.3V5V power source.
2. GND: Connects to the system ground.
3. DO: Digital switch output connected to any digital I/O pin.
4. AO: Analog voltage output connected to an analog input pin.

A separate 2-pin header links the control board directly to the external rain-sensing pad using jumper wires.