How to erase flash memory in NRF52840 USB Dongle

[Martin Muhady]

Hi,

I'm collecting data from BLE and storing them into nRF52840 Dongle by using nrf_fstorage_write procedure. Everything works fine so I can write data into flash by  nrf_fstorage_write and read them by nrf_fstorage_read. Now I'd like to erase all my data stored in Dongle. How can I do it? When I try to use nRF Connect - Programmer button "Erase all" is dimmed.

It works only for nRF dev kit :-(.

Thank you.

Martin

[Simonr]

Hi Martin

If you erase all flash on your Dongle, you will lose the bootloader and MBR as well, making it useless until you have recovered it as described in this tutorial. You can do a sector erase to to erase the parts that won't "damage" the UICR, but that requires a debugger. The erase button in nRF Connect Programmer will always keep UICR, MBR and the Bootloader, and is whited out when there is nothing else to erase.

I strongly recommend that you don't erase all on the Dongle, but you can do it by using nrfjprog -e in the command window. If you still want/have to do it, please check out the aforementioned tutorial to make sure you will be able to recover it first. 

Best regards,

Simon

[Martin Muhady]

Thank you for reply but now I'm bit confused. My intention is to erase custom application data from my dongle. When I use dev kit (not dongle) I use "erase & write" button and it's done. Here is a print screen how it looks like:

When I use programmer for dongle I see this:

So, how can I erase custom app data from dongle? Thank you a lot.

[Simonr]

Hi

The Erase all and Erase & Write won't work without an onboard debugger. If you want to do an erase all you will have to use an external debugger. Again, see our nRF52840 Dongle tutorial for how to do this. I don't think the bootloader supports erasing just custom app data. 

Best regards,

SImon

[Martin Muhady]

Thank you a lot for your help. On the end I decided to do it by myself by using //remove data
nrf_fstorage_erase(&fstorage,magicaddr,100,NULL);