Cold-chain temperature monitor — a personal IoT project

Why I built it

Anyone storing something temperature-sensitive — vaccines, food, chemicals — usually finds out about a problem after the damage is done, from a log nobody read. I wanted to see how far you could get toward catching it before the loss, rather than reporting it afterwards.

What it does

• Live dashboard. Sensor readings arrive continuously and the screen updates itself; no refreshing, no exporting.
• Alerts when something drifts. Each device has its own safe range, and going outside it raises an alert that someone has to actually resolve.
• Notices when a sensor goes quiet. A silent sensor is a failure too — if a device stops reporting, that’s flagged rather than ignored.
• A forecast, not just a reading. Recent history is used to project where the temperature is heading, so the screen turns red before the limit is crossed instead of after.
• Reports over any period, for the paperwork that inevitably follows.

How it turned out

Working end to end, with a built-in sensor simulator so the whole system can be demonstrated without any hardware plugged in. It’s the piece I’d start from for a real cold-storage or laboratory client rather than building from scratch.