Demo: https://signaltower.netlify.app
The demo uses your phone's flashlight to prove the concept, but the same Web Serial/WebUSB APIs can control real PLCs and signal towers.
Traditional setup: ~$15K (HMI panel + signal tower + licenses) This setup: $15 Raspberry Pi
You can test it standalone or install it in GnokeStation by typing "install [signaltower-url]" in the terminal.
Current state: Working proof of concept. Looking for feedback on the industrial control approach and potential production use cases.