Local IP address to QR-code

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

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