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Lab 31. JsonServer+Node-RED

Lab 31. JsonServer+Node-RED

Dec 14, 2016

Expected completion time of this lab: 

.

Node-RED is fun little tool from IBM Research to "wire up the IoT". You will use the JsonServer application to interface Node-RED to your SmartMesh IP network.





Overview of Node-RED

Node-RED is fun tool from IBM Research to "wire up the IoT". It's a little program you launch of your computer, which allows you link inputs (sensors, etc.) to outputs (actuators, files, Twitter feeds, etc) through a web-based graphical interface.

Crash Course 31.1 (given by your instructor)

What is Node-RED?

Setup

Installing Node-RED

The first step is to install Node-RED.

  • First, install Node.js. There a number of options. On a Windows machine, it just means downloading an installer and clicking through the default installation options.

  • Verify Node.js is installed by entering the following command (npm is the "node package manager", part of Node.js)


C:\Users\twatteyne>npm --version 2.15.9

  • Install Node-RED through npm:

npm install -g --unsafe-perm node-red

  • Start Node-RED:

C:\Users\twatteyne>node-red Welcome to Node-RED =================== 1 Sep 15:02:04 - [info] Node-RED version: v0.14.6 1 Sep 15:02:04 - [info] Node.js version: v4.5.0 1 Sep 15:02:04 - [info] Windows_NT 6.1.7601 x64 LE 1 Sep 15:02:04 - [info] Loading palette nodes 1 Sep 15:02:05 - [warn] ------------------------------------------------------ 1 Sep 15:02:05 - [warn] [rpi-gpio] Info : Ignoring Raspberry Pi specific node 1 Sep 15:02:05 - [warn] [tail] Not currently supported on Windows. 1 Sep 15:02:05 - [warn] ------------------------------------------------------ 1 Sep 15:02:05 - [info] Settings file : C:\Users\twatteyne\AppData\Roaming\npm\ node_modules\node-red\settings.js 1 Sep 15:02:05 - [info] User directory : \Users\twatteyne\.node-red 1 Sep 15:02:05 - [info] Flows file : \Users\twatteyne\.node-red\flows_HDC_SW 01.json 1 Sep 15:02:05 - [info] Creating new flow file 1 Sep 15:02:05 - [info] Starting flows 1 Sep 15:02:05 - [info] Started flows 1 Sep 15:02:05 - [info] Server now running at http://127.0.0.1:1880/





Running the JsonServer application

Crash Course 31.1 (given by your instructor)

The JsonServer application.

This application is part of the SmartMesh SDK. To start it, double-click on JsonServer.py.

Starting your network

We assume that you have a SmartMesh IP manager connected to the computer which runs the JsonServer application, and a couple of motes already in the network.

Interact with your SmartMesh IP nodes using Node-RED!

In this section, we will create a number of Node-RED flows to interact with your SmartMesh IP network directly from Node-RED!

Retrieve the status of the JsonServer

Create a flow in Node-RED to issue the following HTTP request:

method

GET

URI

http://127.0.0.1:8080/api/v1/status

body

none

  • What is the response from the manager?

List the available serial ports

Use Node-RED to issue the following HTTP request:

method

GET

URI

http://127.0.0.1:8080/api/v1/helpers/serialports

body

none

  • What is the response from the manager?

Connect to your SmartMesh IP Manager

Use Node-RED to issue the following HTTP request:

method

PUT

URI

http://127.0.0.1:8080/api/v1/config/managers

body

{
"managers": ["COM10"]
}

Replace the serial port number above by yours.



  • After you issue this command, retrieve the status of the manager. What is the status of your manager?

List operational motes

Use Node-RED to issue the following HTTP request:

method

GET

URI

http://127.0.0.1:8080/api/v1/helpers/motes

body

none





  • What is the response from the manager?

Blink LEDs on motes

Use Node-RED to issue the following HTTP request:

method

PUT

URI

http://127.0.0.1:8080/api/v1/oap/00-17-0d-00-00-38-06-45/digital_out/INDICATOR_0

body

{ "value":1}

  • What is the configuration of the "LED on" widget?

  • What is the configuration of the "LED off" widget?

  • What is the configuration of the "http request" widget?

Display temperature readings

Use Node-RED to receive the following HTTP requests

method

POST

URI

/oap

Add a function so the debug console prints only the temperature values received, in C.

  • What is the configuration of the "function" widget?

A little control loop!

Install the following control loop: set the LED of one mote iif the temperature measured by the other mote is larger than 20C, clear otherwise:


MQTT integration!

Crash Course 31.1 (given by your instructor)

MQTT and HiveMQ.

MQTT allows you to coordinate two independents flows, possibly running on different computers.

For that, create two flows: