Hardware & IoTLesson 103Free preview

RasPi WebSocket

This lesson is part of Node.js · All levels

Summary

This lesson builds a complete application: a web server on Raspberry Pi that controls GPIO via WebSocket so that the button/LED status appears in real time in the browser. You're going to combine the HTTP, fs, and ws modules to present a page as a two-way message channel. This pattern became the basis of the home IoT dashboard.

Key points

One server serves a static page and a WebSocket connection on the same port. (index.html)
The event watch button is sent to the browser via JSON.
The browser's commands (e.g. {'action':'led','value':1}) are received via ws.on('message').
Broadcast to many browser tabs using iterations over connected clients.
Use a ping/pong heartbeat to detect and clear the dead connection.

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