Factory reset or clearing - The Nano V1 altimeter manual

You can clear the Nano's flight logs, or wipe it right back to its factory settings, in a few different ways. You might do this to clear the Nano before a competition, undo settings you no longer want, or pass the altimeter on to someone else.

Before you start

Every method below deletes the flight logs stored on the Nano, and they can't be recovered afterwards. Upload any flights you want to keep to the Altimeter Cloud first; once they're there you can always download them again.

Method	Flight logs	Settings
Hold the button 10 seconds (contest reset)	Deleted	Kept
Hold the button 22 seconds	Deleted	Back to defaults
`factoryreset` in the settings file	Deleted	Back to defaults
Full install with the update tool	Deleted	Back to defaults

After a contest reset, flight numbers carry on from the last one. After a full reset by any method, they start again at 1. Your IMU calibration is kept.

With the button

This needs no computer and works in flight mode or USB mode, as long as the Nano isn't recording or saving a flight. Press and hold the button and watch the LED:

Hold for	LED	What happens
4 to 10 seconds	Red flashing, speeding up	A warning. Let go now and nothing is deleted
10 seconds	Solid red	Contest reset. Every flight log is deleted and your settings are kept. Let go here
12 to 22 seconds	Red and blue alternating	A second warning. Let go now and only the logs are deleted
22 seconds	Solid red, then dark	Full reset. The storage is formatted and every setting goes back to its default

Once you let go after 10 seconds or more, the Nano restarts.

Don't hold it while switching on

Press the button with the Nano already on. Holding it while you switch on can start the processor in its programming mode instead.

Checking a Nano is empty

When the Nano is ready for flight, its green ready flash is a single flash if no flight logs are stored, and a triple flash if it already holds a flight. So after a contest reset you should see single green flashes.

With the settings file

Connect the Nano by USB and open device_settings.txt on its drive.
Change "factoryreset": 0 to "factoryreset": 1, save the file and eject the drive.
Unplug the Nano, or switch it off and on. It resets at the next power-on.

The fresh settings file it writes has factoryreset back at 0, so it only resets once.

With the firmware update tool

Installing the firmware with the Full option in the firmware update tool replaces the Nano's whole memory, so it starts up as a fresh device on the latest firmware. The normal Update option leaves your settings and flights alone, so it doesn't reset anything. The firmware updates page has the full steps.

Open the firmware update tool ↗

After a reset

The Nano clears what it needs to, writes out a fresh set of default files on its drive, and restarts itself a few times along the way. This takes around 20 seconds and is completely normal. Let it finish on its own before you unplug it or expect its drive to appear.