# Temperature and humidity sensor, HTU21D, I2C, 1.5-3.6V

- Page: https://sigmanortec.ro/en/temperature-and-humidity-sensor-htu21d-i2c-15-36v
- Price: 17.22 RON
- Availability: In stock; 1-2 zile
- Reference: 9570 · EAN: 5948925466103
- Category: Mechatronics and IoT > Sensors and Modules > Temperature and Environmental Sensors
- Specifications: Supply Voltage: 1.5; Maximum Input Voltage: 3.6; Input Voltage Type: “DC” in Romanian can mean **“de ce”**, which translates to **“why”** in English.
- Package (shipping data): 0.002 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 04:49 (Europe/Bucharest)

## Description

Precision module for measuring temperature and humidity in Arduino projects and other boards, with fast I2C communication and very low power consumption. It operates at 1.5-3.6V with 3.3V supply, offers 0-100% RH and -40 to 105C measurement, with typical accuracy of ±2% RH and ±1C. It has 4 pins VCC, GND, SDA, SCL and configurable pull-up resistors.
Precision sensor for temperature and humidity, HTU21D, compatible with Arduino and other development boards, which communicates with the microcontroller via I2C. The sensor is compatible with logic voltages up to 3.3V, this means that a logic level converter will be necessary if it is used with development boards that work with a logic voltage of 5V or higher. alternatively, a 10K resistor can be added on the SD and SCL lines when used with 5V development boards.
The board has 4 pins, 2 for power (VCC and GND) and 2 for communication (SDA and SCL). There is a 4.7K "pull up" resistor for I2C communication. When connecting several devices to the same bus, these resistors will have to be deactivated. From the factory, the board comes with the resistors disabled. To activate the resistors, solder the 3 jumpers together on the board.
For use with Arduino, the "HTU21D.h" library will be installed and can be tested using the example code related to this library.
Pins:
3.3V: 3.3VDC power supply
GND: GND
SDA: Pin A4 (or SDA) of the UNO board
SCL: Pin A5 (or SCL) of the UNO board
Specifications:
Supply voltage: 3.3VDC
Logic voltage: 1.5 - 3.6VDC
Communication: I2C
Integrated: HTU21D
Measured humidity range: 0 - 100%, avoid exposure to condensation and water
Accuracy of measured humidity: +-2%
Measured temperature range: -40 - 105 degrees C
Accuracy of measured temperature: +- 1 degree C
Maximum consumption: 2.7uW
Measurement interval: 50ms
Response time: 5s
Dimensions mm: 15.5 x 15.5mm