Send data from NodeMCU to Raspberry Pi using MQTT

Objectives

• Set up NodeMCU to communicate to an MQTT server
• Set up an MQTT server on Raspberry Pi
• Send data from NodeMCU to Raspberry Pi

Things

1. NodeMCU
2. Breadboard
3. Raspberry Pi
4. Micro USB cable

Let’s begin!

MQTT is a communication protocol used to communicate between connected devices. Devices can publish data and several other devices can subscribe to the data published by other devices. In our case, the NodeMCU will publish data and the Raspberry Pi will be subscribed to the NodeMCU’s data.

Note: If for any reason, you do not have Arduino IDE or NodeMCU installed on your Arduino IDE, follow the steps in this unit.

Setting up the NodeMCU for MQTT Communication

Install PubSubClient by Nick O’Leary on the Arduino IDE

Step 1: Navigate to Sketch->Include library->Manage libraries…

Step 2: Search for PubSubClient

Step 3: Install the library PubSubClient by Nick O’Leary

Interfacing NodeMCU with IR sensor (analog)

Setting up Raspberry Pi for MQTT Communication

We will install paho MQTT to use in Python and Mosquitto to use from the terminal.

Update everything by typing following command,

sudo apt-get update

sudo apt-get install build-essential python-dev python-openssl

Now let’s install a package called Mosquitto which is an MQTT Client. We can do this by running the command

sudo apt-get install mosquitto mosquitto-clients

In order to install paho enter the following command in your terminal.

pip install paho-mqtt

The mqtt client is now installed.

nano nodemcu.py

Copy paste the following code into the editor. Make sure to change the IP address to the address of your Raspberry Pi.

To run the code, execute the following command

python nodemcu.py