Mega 2560 + WIFI + MQTT

Hi all, I have a simple use case - AIR quality monitor. I think I went in the wrong direction thus I'm looking for help.

  1. What I want to achieve:
    I have MH-Z19B, SGP30, SDS011, BME280. Let's say once a minute I read measurements and send them to the server.

  2. What I have:
    Arduino nano with the sensors connected to it which sends measurements via nrf24l01 to the gateway.

  • one UART
  • not enough memory for connecting everything I want
  • via nrf24l01 I can send only 32 bytes at a time which means saying NO to a nice JSON (splitting payload is not an option)
  • ugly python script on the server which reads bytes and parses it (nrf24l01 receiver is connected to the raspberry pi).

In order to solve UART and memory issues, I got an Arduino Mega.
In order to solve 32 bytes constraint and to get rid of the python script, I got ESP-01...knowing nothing about it.

WiFiEsp library - the only library which works with my ESP-01, and this library is outdated.
MQTT client - which is also outdated (last commit around 2 years ago)
Altogether it is kind of working, at least it sends messages arguing that firmware is not supported and so on.
all other libs simply don't work because of the ESP-01 firmware version. :o

Reading forum back and forth I found information that it is possible to update firmware using programmer which I found only on aliexpress.

Reading further I found the advice from @Juraj to buy Wemos D1 mini or NodeMCu to learn how to work with an esp8266 which sounds reasonable to me.

  1. Finally. Here are my questions:
    Will Wemos D1 mini or NodeMCu help me to achieve what I want?
    What WIFI module that has good software/community support is preferable to use in conjunction with Arduino Mega?

Thank you in advance :slight_smile:

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nrf24l01 is RF not wifi

I concur with the Wemos D1 mini or ESP32 idea.

NodeMcu is firmware it is not a module.


nrf24l01 is RF not wifi

I concur with the Wemos D1 mini or ESP32 idea.

NodeMcu is firmware it is not a module.


Hi, thank you for your reply. I know that nrf24l01 is RF, not wifi.
From what I see now is that my big mistake was not just nrf24l01 but to connect everything to the one board, which is probably pointless.
I think I will end up with a sensor per board that will send data to its own topic(no fat model), thus it will be easier to make statistics and dashboards in the future.