SHT21 Digital Temperature and Humidity Sensor
- GY-21 digital temperature and humidity sensor module based on the SHT21 sensor.
- Provides accurate relative humidity and temperature measurements through a simple I2C digital interface.
- Ideal for weather stations, environmental monitoring, HVAC projects, smart homes, Arduino, ESP32 and other microcontroller applications.
SKU: sht21-digital-temperature-and-humidity
GY-21 SHT21 Temperature & Humidity Sensor
The GY-21 is a compact digital temperature and humidity sensor module based on the Sensirion SHT21. It provides calibrated digital measurements of relative humidity and temperature, making it a convenient alternative to simpler analog or lower-cost humidity sensors.
Communication is handled through an I2C interface, allowing the module to connect directly to compatible microcontrollers such as Arduino, ESP32 and Raspberry Pi. The digital output provides linearized sensor readings without requiring an external analog signal-conditioning circuit.
The GY-21 is suitable for weather stations, indoor environmental monitoring, HVAC systems, humidifiers, smart-home devices, data logging and general temperature and humidity measurement applications. Common GY-21 modules may include onboard regulation and level shifting, allowing connection to both 3.3V and 5V development platforms, depending on the specific module version.
| Product Type | Digital Temperature & Humidity Sensor Module |
|---|---|
| Module | GY-21 |
| Sensor IC | Sensirion SHT21 |
| Humidity Measurement Range | 0–100% RH |
| Humidity Accuracy | Typical ±2% RH |
| Temperature Measurement Range | -40°C to +125°C |
| Temperature Accuracy | Typical ±0.3°C |
| Humidity Resolution | Up to 0.03% RH |
| Temperature Resolution | Up to 0.01°C |
| Interface | I2C |
| I2C Address | 0x40 |
| Sensor Supply Voltage | 2.1–3.6V |
| Module Supply | Common breakout versions support 3.3V or 5V input through onboard circuitry; exact range depends on module design |
| Humidity Response Time | Approximately 8 seconds (63% response) |
| Applications | Weather stations, HVAC, humidifiers, environmental monitoring, smart homes and data logging |
| Compatible Platforms | Arduino, ESP32, Raspberry Pi and other I2C-compatible platforms |
| Module Type | Digital temperature and humidity sensor breakout/module |
