The HTU31-D is the third generation of temperature-humidity sensors from TE - and a great follow-up to the popular HTU21-D sensor. Like the HTU21, the '31 is great for sensing temperature and humidity, with excellent specifications.

This I2C digital humidity sensor is an accurate and intelligent alternative to the common DHT-series sensors, at about the same price! It has a typical accuracy of ±2% at 20% to 100% relative humidity, at a temperature range of 0 to 70°C. Operation outside this range is still possible - just the accuracy might drop a bit. The temperature output has an accuracy of ±0.2°C from -0~100°C, on par with the better quality on-chip sensors we've stocked.

The sensor also has an on-board heater that can be controlled on and off to help evaporate condensation on the sensing element. Of course, temperature sensing will not be accurate with the heater on. Data reads come with CRC, so you can be more confident of data that is read compared to other I2C sensors.

Other nice extras: a hardware reset pin, an address-select pin so you can have two on one I2C bus, and a thermal-isolation cut out so nearby circuitry has less effect on the readings.

To get you going fast, we spun up a custom made PCB in the STEMMA QT form factor, making them easy to interface with. The STEMMA QT connectors on either side are compatible with the SparkFun Qwiic I2C connectors. This allows you to make solderless connections between your development board and the HTU31Ds or to chain them with a wide range of other sensors and accessories using a compatible cable. QT Cable is not included, but we have a variety in the shop. You can use this sensor safely with any kind of microcontroller/microcomputer with 3.3V-5V power or logic.

Each order comes with one fully assembled and tested PCB breakout and a small piece of header. You'll need to solder the header onto the PCB to use in a breadboard but it's fairly easy and takes only a few minutes even for a beginner.