Description: 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’ll 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’re hooking up multiple I2C devices on the same bus, you may want to disable these resistors.
Note: Full drops of water can damage the sensor. We recommend wrapping the board in Teflon/irrigation tape for extreme conditions where water droplets may find their way onto the sensor.
Dimensions: 0.6 x 0.6"
Based on 4 ratings:
2 of 2 found this helpful:
Very easy to interface using the example code and connection circuit. Well labeled board.
Some discrepancy regarding the necessity of resistors in series when using a 5V I2C. The example code on GitHub recommends a 330Ω resistor in series for 5V, the description in the Hook Up Guide states that one doesn’t need to level shift, and the example code link from the Hook Up Guide makes no mention of the resistors. Still, Five Stars to the SparkFun Team for a clearly marked board and well written connection guide. I really had to dig deep into old files before i found the one file that confused me.
Compared with the recently calibrated equipment at the lab. The temperature appeared very accurate (±0.5˚F) at room temperature. The humidity was less accurate (±5 %RH) at 20%RH. For the price, I am happy with this device! Saving the one last star for a device with more accurate humidity. Maybe the SHT15 will do that for me.
Thank you and Happy New Year!
1 of 1 found this helpful:
This review is not only about the HTU21D breakout board, but about SparkFun as a whole.
I was starting to learn electronic (thanks to Arduino) when I fell upon SparkFun and it’s been my crush for 2015. I like everything of it, from the website, to the quality of the pieces provided, going through the persons that answer emails, the articles, the lessons..
And all of that with a lighthearted, humorous tone, which make learning as fun as easy.
I am the kind of person who ask lots of question and its always been the an excellent costumer service. Now about the HTU21D piece itself, once the header are soldered and the linked to your Arduino, just launch the example and everything is working.
I bought a breadboard with the same chip on it from elsewhere (can’t remember from where though) and it’s been a real pain to make the library work. The one from SparkFun works on first try.
Thanks again for all the information, great products, great service. To all, have a great day.
Thank you for the kind words. Happy hacking!
Plugged it in and got good data, THis was nice compared to the TMP36
0 of 1 found this helpful:
Own two, but only one works.