Connection issue using esp8266 and temp sensor

Q&A Forum › Category: Home Automation › Connection issue using esp8266 and temp sensor

David asked 4 years ago

Hi there Guys,
I’m currently working my way through the home automation course and loving it!
Was wondering if you could help?
I’m currently at MODULE 8 – Connecting the ESP8266 – Part 3 unit 1 and can’t seem to get a temp reading on the ESP8266 using the DHT 22 temp sensor.
I found your guide on the DHT sensors helpful and have uploaded the basic sensor test example as suggested but still can’t get any readings. Have also tested the sensor on an arduino uno and got readings straight away.
Any other suggestions?

Thanks,
David

Question Tags: DHT22

9 Answers

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Sara Santos Staff answered 4 years ago

Hi.
What is exactly your DHT22 sensor?
It is the one with three or four pins?
Regards,
Sara

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David answered 4 years ago

Hi Sara,
It’s the 3 pin model (AM2302) with the pull up resistor on the board.
Kind Regards,
David

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Sara Santos Staff answered 4 years ago

With the Arduino, do you power with 5V?

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David answered 4 years ago

Yes, have also confirmed 5V by measuring across pin 1&3.

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Sara Santos Staff answered 4 years ago

I’m not sure based on just those details. You might be using a bad sensor, sometimes the inexpensive sensors can be damaged. We have a dedicated guide about common errors with DHT sensors.

[SOLVED] DHT11/DHT22 – Failed to read from DHT sensor

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David answered 4 years ago

One last question 🙂 (on this subject)
I have tested and got the the DHT11 & DHT22 temperature sensors working on other boards but still can’t get them working on the esp8266???
So it has to be the board rather than a bad sensor.
The board is a LoLin NodeMcu V3 LUA Development Board ESP8266 (12E) WiFi
Thanks,
David

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David answered 4 years ago

Re-flashed it using NodeMCU firmware and changed all cables and is now working!?! 🙂
Thankfully

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Sara Santos Staff answered 4 years ago

Great.
I’m glad it is working now.
It’s weird. But sometimes, weird stuff happens in electronics.
Many times, things might not be connected properly because of the cables (may be faulty).
I’ll mark this issue as resolved, if you need further help, you just need to open a new question in our forum.
Regards,
Sara

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Steve Mercer answered 4 years ago

Agree with Sara here.

Sometimes I get an error (And not always the same error) when I flash my code. Reflashing will always fix that.

With my first ESP32-CAM I did not have an FTDI cable so tried flashing with another ESP32. It would upload OK but always gave an error that it could not find the camera. Ordered new FTDI and USB cable and now works like a charm.