Troubleshooting

Try another USB cable: many only charge, and carry no data. On Windows or an older Mac, a board's USB chip may need its maker's driver: Silicon Labs' for a CP2102 (the Heltec V3's), WCH's for a CH340 or CH9102. Use Chrome or Edge on a computer; Safari and Firefox cannot reach a serial port.

Something else has it open: the browser app in another tab, a serial terminal, the Arduino IDE. Close it and try again.

Put the board in its bootloader by hand: hold PRG, press and let go of RST, let go of PRG, and flash again.

The node says why underneath, and what to do. Most often it is a transmit power more than the region allows with the antenna's gain, or saved data from firmware too different to read: then flash it again as a new board, from the flash page, which gives it a new address.

The node must be on and running Tern; it shows as Tern. It takes one Bluetooth client at a time, so a phone already connected to it hides it from another: disconnect that one. On Android, the app needs its Bluetooth permission, which Android 11 and earlier ask for as location: allow it when asked, or in the app's settings.

Type the passkey the node's screen shows now: it is new each time. If the node was reset, or the app reinstalled, the phone may still hold the old pairing: remove the node from the phone's Bluetooth settings, and on the node forget its phones (the Phones page, or forget on the console), then pair again.

Web Bluetooth is in Chrome and Edge, on a computer and on Android, and not in Safari or Firefox. On Linux, Chrome may need it turned on at chrome://flags. USB works where Bluetooth does not.

• Both must be set to the same region.
• Both should run the same release. Tern is an alpha, and a release may not talk to an earlier one: update both.
• Give them a minute: a node announces itself every few seconds when it starts, and less often after. The node's Nearby page shows whom it hears.
• Check both antennas are fitted, and that the transmit power is not set at its least.

Tern nodes do not hear Meshtastic or MeshCore nodes, and these do not hear Tern: that is by design.

The app says what it waits for:

• Looking for a route: your node has not yet heard of a way to theirs. It goes once a route appears; if theirs is far, a relay between you helps.
• Setting up a secure session: the first message to someone waits two or three seconds for the handshake.
• The region's transmit limit: in EU868 a node may send for 10% of any hour, and has used it. The app says about how long until it may send again.
• The radio is busy: another frame is on the air. It goes in a moment.

• Their node may be off, out of reach, or on another region or release.
• If it is someone you have not written to before, your node may be full of sessions: it holds a fixed number. End one you no longer need, from that conversation in the app, and send again.
• If they have not saved you as a contact, their node may turn you away. Their app tells them you asked: ask them to add you.

A reset gives their node a new address, so it is a different node now. Add their new address as a contact, and remove the old one.

It sleeps a minute after the last thing worth seeing, to save the battery: press PRG once to wake it. If a press does nothing, the node may be off: press again, or plug it in, since it turns itself off when its battery is empty.

It is an estimate from the voltage, good to about ten percent, and reads high while charging. Chg is a guess from the voltage too: a full battery that is plugged in may not show it.

The Reset page erases the node: hold PRG, then hold it again within ten seconds. Its contacts, messages, groups and paired phones go, and it starts with a new address.