Problem PZEM-004T Version 3.0

Thanks Marvin7, the device show up in the Blynk app now but the data does NOT display in the Blynk. Could you please check and let me know if the “mapping” on the Sketch/Setting is correct or not?
What else did I missed?

Below is the setting on the Blynk App

Blynk display NO data

Is never called (neither by timer not directly), or I can’t find where it is. I strongly suggest you to check some basic examples, how to build a working code, because till now it is a kind of hit-and-miss. You placed delay(1000) in loop, which supposedly will work here, but shouldn’t be there. A timer is an almost MUST HAVE with most Blynk firmwares.

Hi Marvin,

I’m just a normal user with ZERO knowledge in programming therefore it take me weeks or month just to do one project. After spend another 2 hours and I still can’t figure out. I also tried to put in the code and it failed to compile.
Please help to fix this so the data can display on the Blynk.

Put the updateBlynk(); just before this delay(1000); in void loop (). It may work, at least to show you some readings. For proper code You NEED TO call updateBlynk() periodically using a Timer. (Blynk.timer) AND remove this delay… How to set it up please find in or, for example look here

Finally, I was able to have my PZEM working with Blynk. :grinning::grinning::grinning:

Special thanks to:

  • Lubomir for the sketch :pray::pray:
  • Marvin & Blynk for helping me to correct the code :pray::pray:
  • And all other users that contributed to this community, you are all great. :clap::clap:
    Keep up with good work :+1::+1::+1:

Maybe say “thank you” by sharing the final code, wiring diagram etc etc so that others can benefit?



Hi Pete,

Yes, I will post the final code, wiring and instructions on another thread so other users can follows and don’t have to go through all kind off issue that I had :slight_smile:


Congratulations, it would be interesting if you would like to share the project with the related code and wiring. So you can do it. Thank you so much .

Anyone knows how to reset energy pzem 004t V.3.0???

if you are using Tasmota your answer is “HERE”

Физически НЕТ ! В v1. была кнопка , а в v3 только програмно.

Without the use of Tasmota and MQTT, but directly connected to Nodemcu, the whole thing is working properly like version V.1.0. Finally after so much sacrifice I succeeded.:smiling_face_with_three_hearts:

Could you share wire connect!
3v3 nodemcu --> 5V pzem?
Tx --> Rx
Rx–> Tx
Gnd --> gnd pzem


Thank you very much your quick reply. Thank you 1000 times

1 Like

Could you share the code!

Please share the code…

Please don’t keep spamming this thread with requests for the code,



Hi All,

Sorry for all the delay on posting the code as I was out of town for 2 months.

I have create a new topic on how to make the wiring connection and the source code for PZEM-004T with ESP8266 so it can display all the data on Blynk app.

Enjoy and have fun with Blynk app and PZEM


Check out the topic HERE: