Node-RED

Quick Start

1. Inštalácia: https://nodered.org/docs/getting-started/windows
   • Online Node-RED environment FRED: https://fred.sensetecnic.com/
2. START http://localhost:1880/
   • Start Dashboard http://localhost:1880/ui
3. Základy
   • Node-RED Guide http://noderedguide.com
   • Cookbook: https://cookbook.nodered.org/basic/map-between-different-number-ranges
4. Knižnice: obvykle radia cez npm (node package manager), ale mne to velmi neslo, preto odporucam postup priamo z Node-RED menu: Settings -> Palette -> Install
5. Ukladanie: vytvorené flows sa nikam extra neukladajú, ale ak by to náhodou spadlo, prídete o ne. Preto odporúčam cez Menu -> Export uložiť to čo potrebujete
6. Koniec: Ctrl+C

Čo ďalej? Podrobnejšie informácie:

• Node-RED Guide: http://noderedguide.com
• Toto je dolezite pochopit https://nodered.org/docs/user-guide/messages#understanding-the-structure-of-a-message
• Inak vysvetlené messages http://www.steves-internet-guide.com/node-red-message-object/
• A hodi sa asi aj vysvetlenie ako je to s premennymi http://www.steves-internet-guide.com/node-red-variables/
• Dashboard podrobnejšie http://noderedguide.com/lecture-7-node-red-dashboard-part2/
• Komunikácia s IBM Watson https://developer.ibm.com/recipes/tutorials/connecting-raspberry-pi-gateway-watson-iot-using-node-red-part-ii/

Inštalácia

1. Najprv nainštalujeme odtialto Node.js

https://nodejs.org/en/

Čo je node js? Node.js is an open-source, cross-platform, JavaScript runtime environment that executes JavaScript code outside of a web browser. Node.js lets developers use JavaScript to write command line tools and for server-side scripting—running scripts server-side to produce dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a "JavaScript everywhere" paradigm,[6] unifying web-application development around a single programming language, rather than different languages for server- and client-side scripts.

Inštaláciu skontrolujeme

C:\>node --version && npm --version

U mňa bola odozva takáto

v12.14.1
6.13.4

funguje to až keď po inštalácii zavrieme vsetky cmd okna a potom v novootvorenom cmd uz to funguje.

2. Potom nainštalujeme z cmd konzoly Node-RED, pre linuxy je popis na stranke, pre win je trocha zmena:

Spsutit cmd (ale run as administrator)

C:\>npm install -g --unsafe-perm node-red

(mne to skoncilo takto

node-pre-gyp WARN Using request for node-pre-gyp https download

ale nevadilo to)

3. Po instalacii to uz funguje, takze staci spustit z cmd

C:>node-red

Musi to bezat v cmd okne na pozadi stale.

4. A potom, tak ako je to aj v tom cmd okne napisane:

Server now running at http://127.0.0.1:1880/
alebo http://localhost:1880

Viac info tu: https://nodered.org/docs/getting-started/windows

First flow

 https://nodered.org/docs/tutorials/first-flow
 

5. Ukoncenie:

It can then be stopped by pressing Ctrl-C or by closing the terminal window.
Alebo na unixovych strojoch cez KILL a PID

Po inštalácii Node-RED budete mať k dispozícii iba základnú sadu uzlov. Dodatočné uzly je možné inštalovať priamo z editora, ale je to trochu skryté. Musíte kliknúť na ikonu menu v pravej hornej časti obrazovky a v menu vybrať funkciu Manage palette. Vyberiete si záložku Palette/Install. Do vyhľadávania napíšte nasledovné výrazy a nainštalujte si ich.

   node-red-node-serialport
   node-red-dashboard
 

Poznámka: nepotrebujeme ziadnu Arduino specific kniznicu, lebo ideme komunikovat cez seriovy port, co je ovela univerzalnejsie ako Arduino.

Príklad 1

Najjednoduchší základný príklad

[
    {
        "id": "cc236d6c.fe202",
        "type": "inject",
        "z": "176a8127.e35c5f",
        "name": "",
        "topic": "",
        "payload": "{\"Temperature\":27}",
        "payloadType": "str",
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "x": 150,
        "y": 200,
        "wires": [
            [
                "be082013.640bb"
            ]
        ]
    },
    {
        "id": "92282460.c4e178",
        "type": "debug",
        "z": "176a8127.e35c5f",
        "name": "",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "payload",
        "targetType": "msg",
        "x": 810,
        "y": 200,
        "wires": []
    },
    {
        "id": "be082013.640bb",
        "type": "json",
        "z": "176a8127.e35c5f",
        "name": "",
        "property": "payload",
        "action": "",
        "pretty": false,
        "x": 370,
        "y": 200,
        "wires": [
            [
                "3a67409b.6b098"
            ]
        ]
    },
    {
        "id": "3a67409b.6b098",
        "type": "function",
        "z": "176a8127.e35c5f",
        "name": "Temperature",
        "func": "/* extrahujeme len jednu z hodnot */\nmsg.payload =  msg.payload.Temperature;\nreturn msg;",
        "outputs": 1,
        "noerr": 0,
        "x": 570,
        "y": 200,
        "wires": [
            [
                "92282460.c4e178"
            ]
        ]
    }
]

V tychto prikladoch sme použili okrem iného:

• https://discourse.nodered.org/t/multiple-lines-on-a-graph-from-one-message/9315/4
• http://noderedguide.com/tutorial-node-red-dashboards-multiple-lines-on-a-chart/
• https://flows.nodered.org/node/node-red-contrib-ui-level - Pekny indikator

A sem dame jeden priklad na Dashboard s viacerymi prvkami