The MH‑RD Raindrop Detection Sensor Module is a simple rain and water‑drop detector consisting of a nickel‑plated FR‑04 rain board and an LM393 comparator control board. It provides both digital (DO) and analog (AO) outputs, making it ideal for weather monitoring, smart irrigation, and DIY Arduino or Raspberry Pi projects.

Key features

• Large 54 × 40 mm rain board made from double‑sided FR‑04 with nickel‑plated surface for excellent conductivity, oxidation resistance, and long service life.
• Separate 31 × 14.2 mm control PCB with LM393 wide‑voltage comparator, power/output LEDs, and sensitivity adjustment potentiometer.
• Operating voltage 3.3–5 V DC with strong output drive capability over 15 mA, compatible with most 3.3 V and 5 V microcontrollers.
• Dual outputs: digital DO for simple rain/no‑rain detection and analog AO voltage proportional to the amount of water on the sensor surface.
• Mounting holes on the rain board and control board for easy installation in weatherproof enclosures or project boxes.

Specifications

• Rain board size: approx. 54 mm (L) × 40 mm (W).
• Control board size: approx. 31 mm (L) × 14.2 mm (W).
• Working voltage: DC 3.3–5 V.
• Outputs: DO (TTL digital switch output), AO (analog voltage output).
• Comparator IC: LM393 wide‑voltage comparator.
• Output current: > 15 mA.

Pinout and wiring

• VCC: Connect to 3.3–5 V power supply.
• GND: Connect to power ground.
• DO: TTL digital output, HIGH when dry and LOW when rain is detected (threshold set via potentiometer).
• AO: Analog output, connect to MCU ADC pin to measure rainfall intensity.

Package includes

• 1 × Raindrop sensor board (54 × 40 mm).
• 1 × MH‑RD control module PCB (31 × 14.2 mm).
• 1 × 2‑pin Dupont cable set for connection.