Publish Serial Messages to MQTT

... to shutdown printer from gcode (action commands) ... to integrate into node-red

Written and tested under Mainsailos.

steps:

• install node-red
• install mqtt
• install klipper2mqtt script into /home/pi/scripts
• install (copy klipper2mqtt.service to /lib/systemd/system/klipper2mqtt.service) and activate service
• study node-red example flow (if not existing, open an issue first :))

This documentation is not finished. Maybe nobody is interested. :) If you have questions, please open an issue and I may invest more time in documentation.