Water Vapor Sensor with Analog and Digital Moisture Outputs

This Water Vapor Sensor detects moisture, fog, rain, and touch events on its exposed sensing surface. It provides both analog and digital outputs, making it useful for simple rain alarms as well as projects that need a proportional wetness trend.

The sensitivity can be adjusted with the onboard potentiometer, while the analog output can be read by an ADC for gradual humidity or water-film detection. Use it with an OpenELAB Sensor Shield V5 for clean wiring in Arduino experiments.

The sensing surface may contact water droplets, but the connector and electronics are not waterproof. Do not immerse the board or expose the header area to standing water.

Technical Specifications

Board Layout & Label Guide

• Sensing surface: Detects droplets, fog, or moisture film.
• Potentiometer: Adjusts the digital trigger threshold.
• G pin: Power ground.
• V pin: 3.3 V or 5 V power input.
• D pin: Digital threshold output to GPIO.
• A pin: Analog output to ADC.
• Connector area: Keep dry and away from immersion.

Application Scenarios

1. Rain or Water Presence Monitor

Read the sensor surface and print a simple moisture level for roof, window, or tabletop experiments.

const int ANALOG_PIN = A0;const int DIGITAL_PIN = 2;void setup() { pinMode(DIGITAL_PIN, INPUT); Serial.begin(115200);}void loop() { int wetLevel = analogRead(ANALOG_PIN); bool wetSwitch = digitalRead(DIGITAL_PIN) == LOW; Serial.print(“analog=”); Serial.print(wetLevel); Serial.print(” digital_wet=”); Serial.println(wetSwitch ? “yes” : “no”); delay(200);}

2. Automatic Cover Trigger

Use a threshold to trigger a servo, relay, or warning output when water is detected.

const int SENSOR_PIN = A0;const int OUTPUT_PIN = 8;const int WET_THRESHOLD = 500;void setup() { pinMode(OUTPUT_PIN, OUTPUT);}void loop() { int wetLevel = analogRead(SENSOR_PIN); digitalWrite(OUTPUT_PIN, wetLevel > WET_THRESHOLD ? HIGH : LOW); delay(100);}

3. Moisture Trend Logger

Average several samples before logging so droplets, fog, or touch events are easier to compare.

const int SENSOR_PIN = A0;void setup() { Serial.begin(115200);}void loop() { long total = 0; for (int i = 0; i < 16; i++) { total += analogRead(SENSOR_PIN); delay(5); } Serial.print("average_wet_level="); Serial.println(total / 16); delay(1000);}

Packing List

• 1 x Digital Signal Analog Sensor for Water Vapor

FAQ

Q: Can this module work with Arduino?
A: Yes. Connect VCC, GND, and the signal pin to an Arduino-compatible board or an OpenELAB Sensor Shield V5.

Q: Can it work with 3.3 V controllers?
A: Yes for the listed 3.3 V to 5 V modules, but keep analog output within the controller ADC range.

Q: Is calibration required?
A: For threshold or quantitative use, calibrate in the final installation and record baseline readings.

Q: Can I use long wires?
A: Shorter wires are better for analog stability; use averaging in firmware if readings fluctuate.

Q: Does the module output precise engineering units?
A: Most of these modules provide relative analog or digital signals, not certified measurement data.

Q: What should I check first if it does not trigger?
A: Verify power, ground, pin mapping, threshold setting, and whether the signal is active-high or active-low.

Q: Is it suitable outdoors?
A: Only with enclosure protection. Keep connectors and electronics away from water and corrosion.

Q: Can it drive a relay or motor directly?
A: No. Use the module as an input to a controller, then drive a suitable relay or motor driver.