Nordic-Thingy52-FW-master doesn't work for my thingy52

[Frankie211]

I didn't change anything and compile the source file from github. But my thingy52 keeps flashing and stays in DFU mode after new app hexfile was burned in

https://github.com/NordicSemiconductor/Nordic-Thingy52-FW 

Need help for this? thanks!!

[Hung Bui]

Hi Frankie, 

By default on the Thingy 52 there is a bootloader. If you flash the application directly via a programmer, the bootloader will reject the image and stay in DFU mode. 

So you either need to do a full erase (nrfjprog --eraseall) to remove the bootloader and then flash your applicaiton. Or you need to do DFU to update your application via the bootloader. 

[Frankie211]

From the tutorial, I need to generate my own public and private key pair and update the bootloader with new public key if I would like to make thiny52 work with custom firmware even I don't change anything with source files. I can update bootloader with new public key via programmer but how about application? It looks like the only way to update is to generate a DFU package with key file and update it with nRF connect. Can I update the custom firmware through programmer(J-Link)?

BTW, a full erase will remove bootloader, does it mean I can develop custom firmware without bootloader?

thanks!!

[Hung Bui]

Yes, if you are planning to develop your own firmware, it's better to get rid of the bootloader. Doing that you can simply flash the application and run it like you do with a development kit. 
If in the future you want to have a bootloader for DFU, you can flash the bootloader back again and update your application using DFU instead of the programmer. 

[Frankie211]

Could I debug my own firmware without a development kit such as nRF52 DK? It seems doesn't work with J-Link programmer only. The PC(program counter) stays in 0xFFFFFFFE after debug session is started in Keil where is not main function located.

[Hung Bui]

Hi Frankie, 
The Jlink programmer should work, but you need to make sure you provide the board with VDD (turn the switch on with battery charged) 

Can you do eraseall and can program some simple application to the Thingy ?