Getting started with Raspberry Pi node red and IoT

Leandro Ramalho edited this page May 9, 2016 · 6 revisions

In this tutorial we will learn how to set up a Raspberry Pi development board and get it to run a blinking LED loop in johnny-five inside of node-red and connect it to the Internet of Things.

Install Raspbian

You will need the Raspbian Jessie image installed on the pi. This doc was written based on the 2015-21-11 release.

You will also need to have network configured. Wifi or wired ethernet will do.

Update the init script.

As of this writing, node.js (version 0.10.29) and the node-red application come pre-installed on raspbian, however for us to use johnny-five we'll need to run node-red as the root user.

Edit the /etc/init.d/nodred script in your favorite text editor on the pi. Switch the line containing USER=pi to USER=root

In the latest version of raspbian (2016-03-18-raspbian-jessie), the script file is /lib/systemd/system/nodered.service.

Trying node-red

Run sudo node-red-start the open a web browser to http://<YOUR PI's IP ADDRESS>:1880

node-red

The startup also created a /root/.node-red folder which contains settings node-red to allow you to set an admin password as well as configure things like the port number.

Adding npm

The raspbian image doesn't include npm, however it is easy to install:

sudo apt-get update

sudo apt-get install npm

Unfortunately this only gets us npm version 1.4.21 which wont work for us, but that's easily updatable:

sudo npm i npm -g

Adding johnny-five

We'll need to add some packages to node-red for johnny-five in the root's .node-red directory:

sudo su -

cd .node-red

npm i node-red-contrib-gpio

That takes a couple of minutes to finish on a raspberry pi 2, and gets us the GPIO and johnny-five nodes. At this point we could plug in an arduino uno to a USB port and get started, however let's add raspi-io so that we can use the pi's onboard pins.

npm i raspi-io

At this point we'll need to reboot.

sudo reboot

Then start node red up again.

sudo node-red-start

Blinking an LED

Once again, point your browser to http://<YOUR PI's IP ADDRESS>:1880

Drop a johnny-five node into the node-red workspace and double click it. Click the edit button to configure a new nodebot, and select Raspberry Pi as the nodebot type and click Add.

add pi nodebot

Then in the onReady code block you can do something like:

var led = new five.Led('GPIO4');

led.blink(500);

Click the deploy button on the upper-right of node-red.

If you have an LED connected to GPIO4 it should start blinking!

Let's add some Internet of Things messaging.

Node-red comes with things like websocket and MQTT nodes. Another really cool set of nodes to add to help connect devices are the nodes for the open source meshblu project.

From the same /root/.node-red directory, we can run:

npm i node-red-contrib-meshblu

This gets us some new input and output nodes for sending IoT messages.

meshblu nodes

More johnny-five components.

The node-red-contrib-gpio nodes already includes all of johnny-five, and there's a ton of other johnny-five related libraries we can easily include by installing them with npm.

Let's use oled-js for example.

npm i oled-js oled-font-5x7

Now in our johnny-five node we can do something like this:

var Oled = require('oled-js');
var font = require('oled-font-5x7');

var opts = {
    width: 128,
    height: 64,
    address: 0x3C
};

var oled = new Oled(board, five, opts);
oled.turnOnDisplay();
oled.clearDisplay();

oled.setCursor(1, 1);
oled.writeString(font, 1, 'Hello, node red !', 1, true, 2);

hello nodered

Doing something with IoT message data.

Perhaps we want incoming messages to do something to our nodebot.

We can use node-red to connect an inbound message node to the input of our johnny-five node.

hello nodered

In our johnny-five node we can listen for events and do something with the data, like writing it to our oled screen:

node.on('input', function(msg){
    oled.clearDisplay();
    oled.setCursor(1, 1);
    oled.writeString(font, 1, String(msg.payload), 1, true, 2);
});

Make a twitter button.

We can connect the output of our johnny-five node to any other type of node.

hello nodered

Then just wire up a physical button to your board, handle button press events by passing a new message along:

var button = new five.Button("GPIO4");

button.on("press", function() {
    node.send({payload: "johnny-five is awesome!"});
});