Local IP address to QR-code

README.md

This flow reads the IP address, generates and displays a QR-code.

This eases the use of a smartphone to connect to the dashboard by reading the QR-code.

The final IP address can be customised with the customise node:

msg.payload = payload.networkInterfaces.*.address[$contains($, /192./)]
msg.payload = "http://" & payload & ":1880/ui"

The exec node should mention the exact path to qr for Command.

Here, the exact path is /usr/local/bin/qr, obtained with which:

% which qr
/usr/local/bin/qr

External dependencies

The flow requires an external QR-code generator, like the qrcode Python package.

Install Python packages image and qrcode with

pip3 install image
pip3 install qrcode

Usage: qr "Some text" > test.png

Usage: qr "Some text"

Reference: https://pypi.org/project/PyQRCode/

Node-RED dependencies

• node-red-dashboard to display the image
• node-red-node-base64 to format the image
• node-red-contrib-os to read the IP address, could be replaced by another solution
• node-red-contrib-image-output to debug the flow, could be omitted

flow.json

[{
	"id": "d97b2960.f2ef38",
	"type": "inject",
	"z": "b37f3718.862418",
	"name": "",
	"repeat": "",
	"crontab": "",
	"once": false,
	"onceDelay": 0.1,
	"topic": "",
	"payload": "",
	"payloadType": "date",
	"x": 100,
	"y": 100,
	"wires": [
		["ad89142b.50f378"]
	]
}, {
	"id": "ad89142b.50f378",
	"type": "NetworkIntf",
	"z": "b37f3718.862418",
	"name": "",
	"x": 250,
	"y": 180,
	"wires": [
		["7b963bb2.0417b4", "ea0a8f5.96bf27"]
	]
}, {
	"id": "ea0a8f5.96bf27",
	"type": "debug",
	"z": "b37f3718.862418",
	"name": "",
	"active": true,
	"tosidebar": true,
	"console": false,
	"tostatus": false,
	"complete": "payload",
	"targetType": "msg",
	"x": 610,
	"y": 120,
	"wires": []
}, {
	"id": "7b963bb2.0417b4",
	"type": "change",
	"z": "b37f3718.862418",
	"name": "customise",
	"rules": [{
		"t": "set",
		"p": "payload",
		"pt": "msg",
		"to": "payload.networkInterfaces.*.address[$contains($, /192./)]",
		"tot": "jsonata"
	}, {
		"t": "set",
		"p": "payload",
		"pt": "msg",
		"to": "\"http://\" & payload & \":1880/ui\"",
		"tot": "jsonata"
	}],
	"action": "",
	"property": "",
	"from": "",
	"to": "",
	"reg": false,
	"x": 250,
	"y": 240,
	"wires": [
		["a92167b8.867b88", "45311f2f.c7238"]
	]
}, {
	"id": "a92167b8.867b88",
	"type": "debug",
	"z": "b37f3718.862418",
	"name": "",
	"active": true,
	"tosidebar": true,
	"console": false,
	"tostatus": false,
	"complete": "payload",
	"targetType": "msg",
	"x": 610,
	"y": 180,
	"wires": []
}, {
	"id": "45311f2f.c7238",
	"type": "exec",
	"z": "b37f3718.862418",
	"command": "/usr/local/bin/qr",
	"addpay": true,
	"append": "",
	"useSpawn": "false",
	"timer": "",
	"oldrc": false,
	"name": "",
	"x": 260,
	"y": 300,
	"wires": [
		["8328eade.ee9fb8", "a91232de.6e35d"],
		[],
		[]
	]
}, {
	"id": "8328eade.ee9fb8",
	"type": "image",
	"z": "b37f3718.862418",
	"name": "",
	"width": 160,
	"data": "payload",
	"dataType": "msg",
	"thumbnail": false,
	"active": true,
	"pass": false,
	"outputs": 0,
	"x": 620,
	"y": 220,
	"wires": []
}, {
	"id": "a91232de.6e35d",
	"type": "base64",
	"z": "b37f3718.862418",
	"name": "",
	"action": "str",
	"property": "payload",
	"x": 240,
	"y": 440,
	"wires": [
		["5d5246ef.73c568"]
	]
}, {
	"id": "5d5246ef.73c568",
	"type": "template",
	"z": "b37f3718.862418",
	"name": "",
	"field": "payload",
	"fieldType": "msg",
	"format": "handlebars",
	"syntax": "mustache",
	"template": "<img src=\"data:image/png;base64,{{{payload}}}\">",
	"output": "str",
	"x": 420,
	"y": 440,
	"wires": [
		["86a168e6.3c2c58"]
	]
}, {
	"id": "86a168e6.3c2c58",
	"type": "ui_template",
	"z": "b37f3718.862418",
	"group": "890778c.fdea288",
	"name": "",
	"order": 0,
	"width": "6",
	"height": "6",
	"format": "<div ng-bind-html=\"msg.payload\"></div>",
	"storeOutMessages": true,
	"fwdInMessages": true,
	"resendOnRefresh": false,
	"templateScope": "local",
	"x": 600,
	"y": 440,
	"wires": [
		[]
	]
}, {
	"id": "428e3733.b85b88",
	"type": "comment",
	"z": "b37f3718.862418",
	"name": "Local IP to QRcode",
	"info": "\nRequires an external QR-code generator\n\nInstall Python packages `image` and `qrcode`\n\n```\npip3 install image\npip3 install qrcode\n```\n\nUsage: `qr \"Some text\" > test.png`\nUsage: `qr \"Some text\"`\n\n+ https://pypi.org/project/PyQRCode/",
	"x": 370,
	"y": 60,
	"wires": []
}, {
	"id": "5e71dd35.5f4fe4",
	"type": "ui_button",
	"z": "b37f3718.862418",
	"name": "",
	"group": "890778c.fdea288",
	"order": 1,
	"width": 0,
	"height": 0,
	"passthru": false,
	"label": "button",
	"tooltip": "",
	"color": "",
	"bgcolor": "",
	"icon": "",
	"payload": "",
	"payloadType": "str",
	"topic": "",
	"x": 110,
	"y": 60,
	"wires": [
		["ad89142b.50f378"]
	]
}, {
	"id": "890778c.fdea288",
	"type": "ui_group",
	"z": "",
	"name": "Default",
	"tab": "618d5f4c.a95f",
	"order": 1,
	"disp": true,
	"width": "6",
	"collapse": false
}, {
	"id": "618d5f4c.a95f",
	"type": "ui_tab",
	"z": "",
	"name": "Home",
	"icon": "dashboard"
}]

Hello to all,
I can run the qr command with putty but I can not run it in the node-red with exec node.Could you help me ?

Are you running the flow?

The exec node may need to have the path to qr adapted to your configuration.

Yes, i am running the flow. Also i tried to write complete command in exec node but i took same error. İ dont understand the reason of fault .

You may try /usr/local/bin/qr instead of qr in the exec node.