Reliability of DHT32

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Joined: Fri Oct 16, 2020 10:46 pm

Reliability of DHT32

Postby rpd1146 » Fri Oct 16, 2020 11:09 pm

I am trying to develop a module to read the temperature using an ESP32 with a DHT22.
I have it on a breadboard and am using the code that can be found in any number of places.
Sometimes it runs, more often it does not, though waggling the device can usually persuade it to read correctly for a few cycles, then it returns to getting the nan error.
On occasions it has run without problem for the best part of a day.
I have tried several devices and all behave in a similar manner. I had hoped that it was a connection problem in the breadboard as they have rather thin legs.
I have now built a final unit and I have the same issue, though I now know that all my connections are good. In this solution, the DHT22 is firmly attached, though it is possible to move it slightly and as before, it can be persuaded to function briefly.
I have tried different read periods out to 1 minute between reads, though my planned period is 5 seconds.
I have tried different resistor values as suggested in some posts. I have read suggestions that running at 5v helps, but I am reluctant to run it at that with a 3.3v device, though I have upped the voltage a little to just below 4v.
None of these had any effect. It is almost as though the internal connection is intermittent and very susceptible to movement.
It clearly is capable of functioning when everything is good.
Has anyone else experienced problems of this nature and can suggest a solution.

Regards, Paul Dixon

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