Not every IoT device needs a cloud dashboard or a mobile app. In many cases the best user interface is already in the user pocket: a browser.

This is an English DEV.to draft based on a Silicon LogiX technical article. The canonical source is linked at the end.

Why it matters

ESP32 is powerful enough to expose REST endpoints, serve a compact web UI and keep sensor acquisition deterministic.

A local-first design is useful for commissioning, maintenance, offline environments and privacy-sensitive deployments.

Architecture notes

Use AP mode for first setup and offline diagnostics. Use STA mode when the device joins an existing network.

Separate acquisition tasks from HTTP handling. A ring buffer keeps the latest samples available without unpredictable allocations.

Expose small JSON endpoints for current values, history, configuration and health status.

Keep the web UI static, cacheable and simple.…