Build Instructions

Collapse

• 1

  What is Node-RED?

  It is a very easy, event-driven tool for setting up your own automation system.

  You may also find more formal and precise Node-RED definition on their website: 

  "Node-RED is a programming tool for wiring together hardware devices, APIs and online services in new and interesting ways. It provides a browser-based editor that makes it easy to wire together flows using the wide range of nodes in the palette that can be deployed to its runtime in a single-click.

  " (ref. nodered.org)

  The best way to learn about it, is obviously by doing it by ourselves. There are plenty of resources available on the internet. However this project is sufficient to provide you a basic introduction how get started and integrate your devices built with WiFi Cricket module to your system.
  

• 2

  Installing Node-RED on RPi

  You can find the most up-to-date official instructions how to install Node-RED on Raspberry Pi here: https://nodered.org/docs/getting-started/raspberrypi

  
  

  However, at the time of doing this project it is as simple as executing this single command line on RPi:

  pi@raspberrypi:~ $ bash <(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-nodered)

  
  

  After successful installation we should get the following output:

  All done.  You can now start Node-RED with the command  node-red-start  or using the icon under   Menu / Programming / Node-RED  Then point your browser to localhost:1880 or http://{your_pi_ip-address}:1880

  
  

  For our convenience we would like Node-RED to be running permanently as a service in the background. So whenever we restart RPi the Node-RED system will be automatically started at boot time. All we need is to execute the following commands:

  pi@raspberrypi:~ $ node-red-start
  
  // Press Ctrl-C (it doesn't stop Node-RED it keeps running as a service in a background)
  
  pi@raspberrypi:~ $ sudo systemctl enable nodered.service

  
  

  This is it! Node-RED is up and running in the background. Now we can open the Node-RED editor from any computer / phone which are in the same network as the RPi. In order to do that we need IP of the RPi and we can obtain it with this command:

  pi@raspberrypi:~ $ hostname -I
  192.168.1.126 <- our RPi IP address, yours will be different

  
  

  Now we can open its editor from a web browser using in our case the following address: http://192.168.1.126:1880

  Great we have got the Node-RED up and running.

• 3

  Receiving MQTT messages in Node-RED

  It is a very simple and straight forward way to start receive MQTT data in Node-RED. All we have to do is to create a "mqtt in" node:

  Then we need to configure the mqtt node by double clicking on it and setting up IP and Port. Note you can use any MQTT broker, however for this project we are using our MQTT broker installed on the the same RPi as Node-RED. (see RPi + MQTT project ).

  In our case it is:

  Server: 192.168.1.126 (alternatively you can type localhost)

  Port: 1883

  Temporarily we are going to receive all messages from our MQTT broker by setting up topic as: #

  (Later we will change it to specific topics once we know what device we want to receive data from.)

  Our MQTT receiver is configured. Now we can attach "debug" node to print out all the messages coming from the MQTT broker. Press the "Deploy" button.

  In the debug tab we should see incoming messages from the broker. However it is empty now because we do not have any device sending messages. Let's go and make a simple temperature sensor with Cricket to send data here.

View all 6 instructions