Wake a Puk and pair it

Each Puk ships with a plastic tab through the battery compartment, holding the cell off its contacts so it arrives with a full charge. Pull the tab out. That is the whole power-on procedure — there is no switch and no button to hold.

The Puk starts advertising immediately and shows up in the app within a few seconds. Accept it, and it pairs to your Tali over Bluetooth Low Energy.

What is talking to what

A Puk never touches your Wi-Fi. It talks only to the Tali screen, over Bluetooth, and the screen is the one thing on your network. That is why the Puk runs for around eighteen months on a coin cell: it is not carrying a Wi-Fi radio.

One Tali holds up to ten Puks. Pair them one at a time, and name each one as you go — a pile of identically-named sensors is much harder to sort out later than it is to label now.

If it does not appear

Bring the Puk within arm’s length of the Tali while pairing, then move it to where it will live. A first pairing at long range through a closed metal door is the most common reason a new Puk stays invisible.

Check the tab, too. On one of the earliest versions a manufacturing defect can stop it coming out cleanly, which leaves the battery out of contact — Tali isn’t detecting a Puk covers what to do.