DHT22 sometimes nan value ESP8266

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Rampler
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DHT22 sometimes nan value ESP8266

#1 Post by Rampler » 17 May 2022, 13:39

Hi,
with the latest release (ESP_Easy_mega_20220427_normal_ESP8266_4M1M) a get sometimes no values(nan) from DHT22 sensor.
With the release from 24.12.2021 the DHT22 was working reliable, always valid values.

Wiring is unchanged.
DHT22 is connected to GPIO0-D3. (I know recommended is GPIO-2)

regards Klaus

TD-er
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Re: DHT22 sometimes nan value ESP8266

#2 Post by TD-er » 17 May 2022, 14:38


Rampler
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Re: DHT22 sometimes nan value ESP8266

#3 Post by Rampler » 17 May 2022, 14:50

I am not sure.
My DHT22 ist working most times, only sometimes i get nan.
In the mentioned issue, the DHT22 does not work at all, right ?

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Re: DHT22 sometimes nan value ESP8266

#4 Post by TD-er » 17 May 2022, 14:54

One user reported it was working "sometimes".
And since there has been no change in the code for that specific plugin, I assume it may be caused by other changes in the core Arduino libraries.
To me it looks like it is a timing issue, which may sometimes be just close enough to the correct timings.
Also there are differences among modules and I would not be surprised to see differences based on temperature too, where the sensor may just accept the wrong timings or not.

Until we actually know what causes this, it is hard to tell, but I have a strong feeling this may be related.

Rampler
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Re: DHT22 sometimes nan value ESP8266

#5 Post by Rampler » 17 May 2022, 15:06

OK, thank you.
I will keep eys on it.
Hopefully the timing behavior will be better with one of next releases.

Rampler
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Re: DHT22 sometimes nan value ESP8266

#6 Post by Rampler » 25 Jun 2022, 12:43

I want to check if the last firmware (2022-6-16) will fix this problem.
I would be useful to to check the NaN value inside the rules, is this possible ?
Has anybody checked the new firmware against the NaN behavior ?

Rampler
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Re: DHT22 sometimes nan value ESP8266

#7 Post by Rampler » 29 Jun 2022, 14:08

After a couple of days the NaN problem is not apeared yet with the firmware form 2022-06-16 ...

just for info

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