Wi-Fi temperature sensor & alarm
Know the moment it crosses the line.
Setpoint is a Wi-Fi thermometer that watches your freezer, fridge, rack or greenhouse around the clock and alarms the instant it breaks a threshold you set — by email or webhook, straight to your phone. No hub. No gateway. No subscription to read your own data.
Why Setpoint
Monitoring built to be trusted, not babysat.
No hub required
Talks to your Wi-Fi directly. Nothing extra to buy, plug in, or keep alive on your network.
Threshold alerts
Set a high and low limit per probe. Cross it and Setpoint tells you — the moment it happens, not on the next poll.
Own your data
A dashboard you run yourself. Per-probe min / max / average, full history, one-click CSV export. In our first field test, one probe logged 160,916 readings on a single charge — nothing dropped.
Weeks per charge
A protected 18650 and deep-sleep firmware. Recharge over USB-C; a power switch stops shelf drain.
How it works
From probe to alert in three steps.
Place the probe
Drop the waterproof stainless probe wherever temperature matters — a freezer, a fridge, a tank, a rack. The board carries an I²C header for a future humidity option.
Join your Wi-Fi
Power on and connect in the browser — no app-store download to get started. Setpoint remembers the network and reconnects on its own.
Set the line, walk away
Choose your safe range. Watch it live on the dashboard, and let the alerts do the watching when you can't.
Runs on a machine you already keep on. Setpoint reports to a small, free app on your own PC, mini-PC, NAS, or home server — that always-on box is what keeps your data yours and your alerts firing without the cloud. If you don't already leave a machine running, it isn't the right fit.
Technical specification
The numbers behind the readout.
Sensing
Power
Connectivity
Software & compliance
* Battery life is still being measured and we will not quote a number until it is. It scales with reporting interval and Wi-Fi conditions, and the deep-sleep run that the figure will come from has not been completed — see the field test, which says so too. Specs reflect rev-2 hardware and are subject to change before general availability.
† First field test, always-on at ~1 reading/second: one unit logged 160,916 readings over 46 continuous hours on a single charge — 430,022 across three units, nothing dropped. This is measured data-capture throughput in Setpoint's most power-hungry mode; it is not the deep-sleep battery life the "weeks" figure above refers to, which remains in testing.
Pick your build
Three ways to run Setpoint.
Every unit is the same core board — choose how it's powered and how much you want to build yourself.
Setpoint USB
- Assembled & tested board
- Waterproof temperature probe
- USB-C powered, runs indefinitely
- Enclosure + mounting
Setpoint Battery
- Everything in USB, plus:
- Protected 18650 installed
- Weeks per charge
- Recharge over USB-C
DIY Kit
- Bare carrier board + parts
- Open firmware, flash in browser
- Full build guide
- Battery not included*
Assembled prices (USB / Battery) are indicative for launch; the DIY kit price is live on Tindie. *DIY kits ship without a lithium cell — add a reputable protected or flat-top 18650.
Where it earns its keep
One probe, a lot of things worth not losing.
FAQ
Before you buy.
Do I need a cloud account or a subscription?
No. Setpoint reports to a free app on your own machine over your local network — no account, no telemetry, nothing phoning home. The internet is only touched if you choose to let email alerts leave your network.
What computer do I need to run it?
Any always-on Windows or Linux machine you already keep on — a mini-PC, NAS, home server, or a Raspberry Pi. That local box is what stores your history and fires your alerts without a cloud. If you don't already leave a machine running, Setpoint isn't the right fit.
How accurate is it?
±0.5 °C typical from −10 to +85 °C, uncalibrated (you can add a per-probe offset in the app). Below −10 °C — which includes a typical −18 °C freezer — it is ±2 °C: enough to tell you the freezer has failed, not enough to be a calibrated record. It is not a certified, NIST-traceable, or medical instrument.
Wi-Fi and setup?
2.4 GHz only (no 5 GHz). Setup happens on the device in your browser — join the probe's temporary network, pick yours, done. No phone app to install.
What about the battery?
The portable build runs on one 18650 cell (not included — lithium shipping rules) and recharges over USB-C. Or run it always-on from USB with no cell at all. The DIY kit is cell-not-included; add any reputable protected or flat-top 18650.
Is the firmware open?
Yes — read it, build it, and reflash it from your browser any time. You're never locked into a vendor or a server that can be switched off.
Get an assembled unit first.
The DIY kit is live on Tindie now. Pre-built, pre-flashed Setpoint USB & Battery units are not on sale yet — they ship once FCC Part 15B testing is complete. Join the list and I'll tell you when, with launch pricing.
No spam — launch updates only. One email, then you decide.