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?

[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.

[twittich]

It's on fw. If you want to start from pc then just send a command through uart for example.

https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/uart_example.html

[kfinch]

Hello, 

To get this to work, did you have to modify dfu_trigger_evt_handler() in nrf_dfu_trigger_usb.c? Or is there a cleaner way to make these changes? Just wondering how you got around the trigger library wanting to use the reset pin.

Thanks.

[twittich]

Hello,

i don't use the trigger lib because i have no gpio on reset pin. and the call to go to bootloader is coming over uart from pc app, then run the two lines, mentioned above and reboot into bl.