• Skip to main content
  • Skip to primary sidebar

RNTLab.com

The Ultimate Shortcut to Learn Electronics and Programming with Open Source Hardware and Software

  • Courses
  • Forum
    • Forum
    • Ask Question
  • Shop
  • Account
  • Blog
  • Login

Weird multiple DHT22 behavior

Q&A Forum › Category: ESP8266 › Weird multiple DHT22 behavior
0 Vote Up Vote Down
Carlos Alberto Laport de Miranda asked 5 years ago

Hi all,
I have two DHT22 sensor in the same room, one off them working with an ESP8266-12E (NODE-MCU) and the other working with an ESP8266-01. Both communicate with Node-RED via MQTT (No problems here). The “problem” is they show a 2,5 degrees C difference and more than 20% difference on the humidity readings. They use the same code to calculate and show the readings.
Are the DHT22 this innacurate ? Any thoughts are welcome.
Carlos…

Question Tags: DHT22, ESP8266, MQTT, Node-Red
4 Answers
0 Vote Up Vote Down
Carlos Alberto Laport de Miranda answered 5 years ago

Dashboard
The dashboard showing the readings.

0 Vote Up Vote Down
Carlos Alberto Laport de Miranda answered 5 years ago

Continuing the tests, I mounted 4 other DHT22s with an ESP8266-NodeMCU.

With the following results:

The results are reasonable. The temperature readings within more or less 1% and all but one of the humidity readings being off the 2% tolerance.

Probably the DHT22 that was giving rogue readings is defective.

0 Vote Up Vote Down
Sara Santos Staff answered 5 years ago

Hi.
Sometimes if the sensor is subjected to very high levels of humidity, it will take some time until it is able to detect low levels again.
However, I see that in your case, it is the other way around. So, probably there’s something wrong with that sensor.
Regards,
Sara

0 Vote Up Vote Down
Carlos Alberto Laport de Miranda answered 5 years ago

Ok, I will change the rogue one with one of the 4 that gave “good” readings.
 
Thanks.

Primary Sidebar

Login to Ask or Answer Questions

This Forum is private and it’s only available for members enrolled in our Courses.

Login »

Latest Course Updates

  • [New Edition] Build ESP32-CAM Projects eBook – 2nd Edition April 16, 2025
  • [eBook Updated] Learn ESP32 with Arduino IDE eBook – Version 3.2 April 16, 2025

You must be logged in to view this content.

Contact Support - Refunds - Privacy - Terms - MakerAdvisor.com - Member Login

Copyright © 2013-2025 · RandomNerdTutorials.com · All Rights Reserved

Insert/edit link

Enter the destination URL

Or link to existing content

    No search term specified. Showing recent items. Search or use up and down arrow keys to select an item.