Hygrometer
Measures relative humidity (and optionally temperature) for environmental monitoring projects.
Overview
Hygrometers measure the moisture content of the air as relative humidity (RH%). ArduinoStudio supports the popular DHT series and the precision SHT31 sensor. The component emits sensor-data events with humidity readings, and some sensors also include temperature data.
Supported Sensors
| Sensor | Humidity Range | Accuracy | Interface |
|---|---|---|---|
| DHT11 | 20 – 90% RH | +-5% | 1-Wire (digital pin) |
| DHT21 | 0 – 100% RH | +-3% | 1-Wire (digital pin) |
| DHT22 | 0 – 100% RH | +-2–5% | 1-Wire (digital pin) |
| SHT31 | 0 – 100% RH | +-2% | I2C |
Wiring Guide
DHT11 / DHT21 / DHT22
| Sensor Pin | Arduino Pin |
|---|---|
| VCC | 5V |
| GND | GND |
| Data | Any digital pin + 10k pullup to VCC |
Most DHT breakout boards include the pullup resistor on-board. If using a bare sensor, add a 10k resistor between the Data pin and VCC.
SHT31 (I2C)
| Sensor Pin | Arduino Pin |
|---|---|
| VCC | 3.3V |
| GND | GND |
| SDA | A4 (Uno) / 20 (Mega) |
| SCL | A5 (Uno) / 21 (Mega) |
Usage in ArduinoStudio
Drag the Hygrometer component onto the canvas, select your sensor model, and assign the pin. Humidity data streams continuously. Combine with a thermometer for a complete weather station, or trigger a relay to activate a humidifier/dehumidifier when humidity crosses a threshold.