UPDATED PRODUCT – Adafruit Si7021 Temperature & Humidity Sensor Breakout Board – STEMMA QT / Qwiic

3251 iso ORIG 2020 08

UPDATED PRODUCT – Adafruit Si7021 Temperature & Humidity Sensor Breakout Board – STEMMA QT / Qwiic


As of August 25, 2020, we’ve updated this sensor to be STEMMA QT compatible – that means there’s now an easy way to plug-and-play this sensor without any soldering! The physical shape has changed a little, but the pinout is identical.

It’s summer and you’re sweating and your hair’s all frizzy and all you really want to know is why the weatherman said this morning that today’s relative humidity would max out at a perfectly reasonable 42% when it feels more like 77%. Enter the Si7021 Temperature + Humidity Sensor – the best way to prove the weatherman wrong!

This lovely sensor for Silicon labs has ± 3% relative humidity measurements with a range of 0–80% RH, and ±0.4 °C temperature accuracy at a range of -10 to +85 °C. Great for all of your environmental sensing projects. It uses I2C for data transfer so it works with a wide range of microcontrollers.

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3251 kit ORIG 2020 08

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 LIS331s or to chain them with a wide range of other sensors and accessories using a compatible cable. We’ve of course broken out all the pins to standard headers and added a voltage regulator and level shifting so allow you to use it with either 3.3V or 5V systems such as the Raspberry Pi + Feather series or Arduino Uno respectively.

There’s a PTFE filter to keep the sensor clean, that’s the white flat thing on top. Also comes with some pin header. Some light soldering is required to attach the header for use in a breadboard but it’s easy to do.

Check out our awesome tutorial for how to use it with Arduino or CircuitPython.

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In stock and shipping now!


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