Dark Mode

The NanoVNA-F V3 supports a dark display mode that swaps the bright background for a dark one. This is easier on the eyes in dim environments and reduces battery drain.

Enable dark mode

1. On your PC, create a plain text file named dark_mode.txt.
2. Inside the file, write a single character: 1 (the digit one). Save the file.
3. Put the NanoVNA-F V3 into U-disk mode: hold the middle button while powering on the device.
4. The device appears as a USB drive on your computer.
5. Copy dark_mode.txt to the root of the USB drive.
6. Safely eject the USB drive.
7. Restart the NanoVNA-F V3.

The device will boot with the dark color scheme.

Disable dark mode

Follow the same procedure, but change the content of dark_mode.txt to 0 (zero) and copy it to the device again.

Alternatively, delete the dark_mode.txt file from the USB drive entirely.

Tip

U-disk mode is only entered during power-on. If the device is already running, power it off first, then hold the middle button while turning it back on.

Caution

The file must be named exactly dark_mode.txt (all lowercase, with underscore). Other filenames will be ignored.