Features:

• Uses the I2C interface
• Typical humidity accuracy of ±2%
• Typical temperature accuracy of ±0.3C
• Operates from 0 to 100% humidity but this sensor isn’t recommended for harsh environments where it could come in contact with water (such as rain).
• 3.3V sensor – use inline logic level converters or 10k resistors to limit 5V signals
• Only one HTU21D sensor can reside on the I2C bus at a time
• 100% brand new and high quality
• The HTU21D is a low-cost, easy to use, highly accurate, digital humidity and temperature sensor. This sensor is ideal for environmental sensing and data logging and perfect for a weather stations or humidor control systems. All you need is two lines for I2C communication and you âll have relative humidity readings and very accurate temperature readings as a bonus!
• There are only four pins that need to be hooked up in order to start using this sensor in a project. One for VCC, one for GND, and two data lines for I2C communication. This breakout board has built in 4.7k pull up resistors for I2C communications. If you âre hooking up multiple I2C devices on the same bus, you may want to disable these resistors

Specifications:

• Power supply: 1.5V-3.6V
• Humidity measure range: 0-100%RH
• Temperature measure range:-40degree105degree
• Max. power consumption: 2.7uW
• Communication: I2C
• Humidity precision(10%RH to 95%RH): HTU21D±2%RH
• Humidity delay: +/-1%RH
• Measure time: 50ms
• Year drift: -0.5%RH/year
• Response time: 5s
• Size: 1.5×1.5cm(approx)

Connections: Breakout board to Arduino

• VCC → 3.3V
• GND → GND
• SDA → A4
• SCL → A5

There are only four pins that need to be hooked up in order to start using this sensor in a project. One for VCC, one for GND, and two data lines for I²C communication. On an Arduino board connect the SDA pin on the breakout board to A4 and SCL to A5. If you have a newer Arduino, you can connect the SDA and SCL lines directly to the SDA and SCL lines broken out on the Arduino headers.

This board runs at 3.3V. Be sure to power the board from the 3.3V pin! Because I²C is an open drain signal, there’s no need to worry about level shifting the signal; the 3.3V signal will be adequate to communicate with the Arduino and the signal will never reach a dangerous level for the pins on the HTU21D.

Note:

• This breakout board has built in 4.7k pull up resistors for I²C communications. If you’re hooking up multiple I²C devices on the same bus, you may want to disable these resistors.

Package Include:

• 1 x HTU21D Humidity Sensor