NodeMCU Sensor

A lot has changed since my last connected sensor project in 2013, so I wanted to jump in again to see how the technology has come along. After playing with some Particle Photon stuff, I came across NodeMCU. has lots of  ideas for this board, so I sought to recreate what Achraf Oukheir did there.

Achraf’s project is good, but it left out a lot of details, which I will summarize below. It was only by referencing Adafruit and Instructables for similar projects that I was able to eliminate errors and get the code to work. The other consideration is – if you have stepped away from Arduino for a while – just do yourself a favor and update your IDE first!

Tips and links:

Tip #1 – Update to latest Arduino IDE (unless told otherwise)
Tip #2 – Do not copy code into Notepad and back into Arduino IDE – it may introduce non-compliant quotes or other characters.
Tip #3 – Replace your DHT library with the latest one. The one I had was from 2013/14 and it did not work with this project. I used Adafruit’s library: Adafruit_Sensor
Tip #4 – Get the Blynk library directly from their site. Otherwise you might see an error like the one above.
Tip #5 – Be sure you have the NodeMCU. See this Instructables article.  Select NodeMCU 1.0 ( ESP-12EModule).
Tip #6 – See also Adafruit’s tutorials on this sort of thing. Different WiFi chip, but helpful for wiring.

So what did I think of this device? Things have come a LONG WAY since 2013! The app connectivity with Blynk is great. Less hardware, smaller footprint. The NodeMCU was $7 from – and now the newer version with Bluetooth and more capability is out for only a few more dollars. Crazy! The next step will be to possibly use this platform to create a notification setup for our hot tub for both temp and water level. Still considering Photon for that, but NodeMCU might be a good option too.