DFU only once?

RE: DFU only once?

Stefan Birnir Sverrisson — Fri, 12 Dec 2014 12:36:18 GMT

You should not flash your application with nRFStudio when you use the bootloader . You should flash your softdevice , then bootloader and then use Master Control Panel to upload the the application via the bootloader. If can flash softdevice+bootloader+application from nRFgo Studio but then you must merge all hex files into one hex file and then flash the merged hex file, as described on this thread.

If you are using the the nRF51 development kit, you can press button 7 on the nRFgo motherboard while power resetting in order to again enter bootloader mode.

RE: DFU only once?

Stefan Birnir Sverrisson — Fri, 12 Dec 2014 11:45:09 GMT

What bootloader are you using, i.e from which SDK?

RE: DFU only once?

John — Thu, 11 Dec 2014 14:07:01 GMT

The DFU can perform multiple upgrades. However once you perform an upgrade using the DFU, it retains information so it can tell if the application program is valid. On subsequent resets if the application is valid the DFU initialization code will jump to your application rather than retaining control and presenting the DFU service. You need to do something to cause the DFU to retain control on reset.

In my case, I send my application a command to tell it to enter bootload mode. This command sets a specific value in the GPREGRET register and performs a reset. I modified the initialization code in the DFU to check the GPREGRET register for the specific value, and if it finds the value the DFU init code knows to retain control and present the DFU service.