Live temperature — Nano edge, ESP32 gateway

Live temperature from a bench-built edge node. A Nano reads the sensor, an ESP32 gateway publishes it over MQTT, and a small pipeline stores the history. This page shows live and 24-hour values through an outbound tunnel — no inbound ports on the house.

Overview

This is a small IIoT stack at home scale: remote I/O, a message bus, a historian, and a supervisory view. Temperature is sensed at the edge, handed to a gateway, and published on MQTT. Node-RED files the stream so every point has a timestamp. The public site is not on the home network. An outbound-only tunnel lets the website request the latest reading and a 24-hour window through api/temp.php. The page is just another client — live temperature plus a trend — with the house staying closed to inbound traffic.

Data path

The Arduino Nano is the edge node: it reads the temperature sensor and sends the value over serial. The ESP32 is the gateway: it takes that reading and publishes it over MQTT on the home network. Node-RED catches each message and writes it into a time-series database. A Cloudflare Tunnel exposes only the needed API outbound. This website pulls live and historic temperature through a Bluehost endpoint (api/temp.php) — the browser never talks to the house.

What’s on the page

• Real-time: latest temperature from Influx via PHP (shown in °F; stored as °C)
• Historic: recent points plotted for trend in °F (default last 24h)
• Pump: optional later — same path can drive a control signal when you’re ready