DHT22 tinkering.

Part 1

As I await my replacements parts I figured I’d try a few ideas to attempt a recovery of the defective DHT22.

The first thing I decided to do was to remove the DHT22 from its partial enclosure. (Sensor part was exposed)

Reconnected the sensor node and …. it’s still stuck at 99% humidity.

I blew on it and the temperature changed but not the humidity.

Now that the sensor was out of the enclosure I figured I’d try to put more air past it. Using a blow dryer on cool setting I set it on the DHT22 for a little bit. Nothing.


Okay. Does it need to be reset I thought to myself? It did die when as it’s been out for so long. Perhaps the relative humidity sensor is out of calibration.

I wonder if calibration could be edited in the nodemcu.

In any case I decided to try the blow dryer with the heat setting on as it would reduce the Relative Humidity dramatically.

Which it did very nicely. About a minute.

Feels like 190c. ^_^

Ok so the humidity sensor does move. Surely it just needs recalibration.

There is a sunny break and no rain at the moment in this almost 19day cloudy streak.

Both google and Apple report about 64-65% humidity.

What does the DHT22 report?

Well fantastic….

Let’s try again

I guess waiting for the replacements is the only thing left to do. Unless it’s possible to recalibrate.

**Just had a quick look online. It would seem as though this sensor is self calibrating. Which means that my experience was/is with broken DHT22s.

Part 3 Replacement of the DHT22

3 thoughts on “DHT22 tinkering.

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