MicroPython Forum (Archive)

Posted: **Sun Nov 22, 2020 12:01 pm**

Hi,

I'm trying to read my DHT22 sensor (I think it's a DHT22) on my nodemcu ESP8266 board with micropython 1.13.

I use the following example code for DHT22:

Code: Select all

    import dht
    import machine
    d = dht.DHT22(machine.Pin(4))
    d.measure()
    print(d.temperature()) # eg. 23.6 (°C)
    print(d.humidity())    # eg. 41.3 (% RH)

I seem to get a response for the temperature in the range of 500-600.

However, when I use the DHT11 like this:

Code: Select all

d = dht.DHT11(machine.Pin(4))

I get a more sensible response like 22 (degrees C).

Does this mean I'm probably working with a DHT11 sensor, or do I need to apply some more formatting on the DHT22 value received to make more sense of the output?

Thank you in advance!

Best regards,

Posted: **Sun Nov 22, 2020 12:38 pm**

The code should work as it is. So if using the DHT11 code returns proper values, you probably have a DHT11 sensor (clone).
What about the humidity?

Posted: **Sun Nov 22, 2020 1:04 pm**

Yes, with Humidity it's the same. High values when printing d.humidity() for the DHT22, but (seemingly) correct values for DHT11.

So if it should work like the example code, then I will most likely have the dht11 sensor and not the dht22 sensor.

Thanks for the fast reply!

Best regards,

Posted: **Sun Nov 22, 2020 4:04 pm**

It might help to put a sleep of 1 second between measure() and temperature/humidity() because those sensor can take a while. But haven't used one of those in years, they are not very reliable and accurate.

Posted: **Thu Dec 03, 2020 5:11 pm**

just for feedback and anyone else running into the same problem. I bought a new DHT22 sensor and ran the script again. This time I got the correct values. So I (unknowingly) was using a DHT11 before and therefore the DHT22 module did not work.

MicroPython Forum (Archive)

high value reading DHT22 temperature

high value reading DHT22 temperature

Re: high value reading DHT22 temperature

Re: high value reading DHT22 temperature

Re: high value reading DHT22 temperature

Re: high value reading DHT22 temperature