nRF52840 dongle: Erasing persisted data of Matter Lighting App - canonical/openthread-border-router-snap GitHub Wiki

The factory reset of the Nordic Semiconductor nRF52840 Dongle clears the storage, but not the flash memory. Once done, the Matter application is restarted and placed into BLE discovery mode.

To perform the factory reset:

1. Start the application by opening a serial console

This can be done with Minisim.

2. Press and hold the large white button

(Original image from nRF52840 product page)

The white button is labeled as "SW1". This is the only user programmable button on the dongle.
Continue pressing for 3 seconds after seeing "Release button within 3000ms to cancel" in the logs.
During this period, the "LD2" LED blinks 4 times, in blue color.

This is shown in the following video:

Snippets of relevant logs from the serial console:

...
[00:00:00.370,941] <inf> chip: [SVR]Fabric already commissioned. Disabling BLE advertisement
...
[00:32:53.126,739] <inf> app: Factory Reset Triggered. Release button within 3000ms to cancel.
...
[00:32:56.480,102] <inf> chip: [DL]Performing factory reset
[00:32:56.855,834] <inf> chip: [DL]Erasing Thread persistent info...
[00:00:12.625,488] <inf> app: Init CHIP stack
...
[00:00:01.172,149] <inf> chip: [DL]CHIP task running
[00:00:01.175,079] <inf> chip: [DL]CHIPoBLE advertising started
[00:00:01.176,849] <inf> chip: [DL]NFC Tag emulation started

Now, the device can be discovered over BLE:

$ bluetoothctl scan le | grep Matter
[NEW] Device CA:5E:86:D1:47:92 MatterLight