Start dfu mode or open_bootloader from application by function call

[twittich]

Hello

my setup is s140, nrf52840. it is flashed the open bootloader(usb-serial) , the softdevice and an application and everything works fine, flashing running and updating.

at the moment i use the pinreset method to start dfu mode but i want to implement a function which will do the same.

i looked already at the buttonless dfu, the iot, the ble hrs,  etc.... but i dont know how it can be implemented ???

Can someone give me a hint how to implement it for usb serial ?  i'm completely stuck at the problem.

Thanks in advance

twittich

[Einar Thorsrud]

Hi,

The DFU trigger library in the SDK is designed for this use case. By including it in your application you can trigger DFU bootloader mode by issuing a DFU_DETACH request.

As described in the documentation you need to adapt your HW so that you connect a GPIO pin to the reset pin. Then the DFU trigger library will use this GPIO to trigger reset, entering DFU mode. The library documentation is quite slim, but you can refer to how it is used in <SDK 15.3>\examples\connectivity\ble_connectivity\pca10059\ser_s140_usb_hci\.

[twittich]

Thank you for the fast response.

I can't make changes on the HW and solved it now with this

nrf_power_gpregret_set(0xB1);
NVIC_SystemReset();

so far it works that way or do i get any errors that way?

[Einar Thorsrud]

Hi,

That is OK. Using the retention register and triggering soft reset is a common way signal tot he bootloader that it should enter DFU mode.

[twittich]

Ok thanks

[xaqfan]

Hi ,

May i ask a question? Is  the application  program on FW or PC? 

I want to operate it on PC.