Low-cost temperature and humidity sensor solution -- NTC thermistor + humidity sensor

The purpose of this DIY project is to replace the expensive and easily damaged DHT22 sensor. Since high accuracy is not a primary concern,






four out of the five DHT22 sensors I've used since 2019 have inexplicably failed, exhibiting humidity levels consistently around 20% or 99%. Two of these failures occurred after prolonged periods of disuse.



Furthermore, the design sandwiched the DHT22 between two boards, which, despite the boards not generating much heat, still resulted in a temperature approximately 2 degrees Celsius higher than the actual temperature. Therefore, the temperature sensor should be kept as far away from the PCBA as possible.



This led to the creation of an expansion board, using an NTC sensor and a humidity sensor instead of the DHT22.



Temperature measurement range: -50℃ ~ 99℃; Humidity measurement range: 20% ~ 100%






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[Images 1-20240423_011648.jpg and 1-20240423_011700.jpg are included.]


The humidity sensor has a socket for easy insertion and removal to avoid accuracy changes caused by soldering and to facilitate replacement in case of damage




. [Image 1713806991649.jpg

is included.] The host computer program is just a simple code snippet; it works, and



the code is continuously being improved.