Question - How to enter in DFU mode using open USB bootloader example on pca10056 ?
i tried writing nRF52840DK with examples-DFU-open_botloader-pca10056_usb and usb_debug by SWD debugging port J2 and when i plugged the usb to J3 connector and pressed reset key, nRF52840 is not being recognized by nRF connect application.
The open bootloader example should work out of the box. How do you flash the bootloader hex file ? Have you flashed the softdevice ?
I would suggest to use nrfjprog to flash the softdevice first, and then flash the bootloader.
Since there is no valid application the bootloader shoud start automatically. You should see LED2 lid up and down (breathing)
If you connect USB cable to J3 you should see a SDFU virtual comport created.
However which DK are you using to test ? We have a known issue with PCA10056 DK v0.9.2 that USB on J3 doesn't work. I would suggest to test with PCA10056 from V1.x
If there is a valid application, you can enter DFU mode by triggering a pin reset (SW5) or follow this triggering procedure.
Hi Hung Bui
Thank you for your response.Actually i am new to this, yes i have not flashed the soft device.
what i did was write the nRF5_SDK_15.3.0_59ac345\examples\dfu\open_bootloader\pca10056_usb to a empty PCA10056board
can you tell me which soft device do i need flash ? where can i read guide or steps for USB bootloader dfu
The Open Bootloader is quite new so we don't have good documentation for it. What you basically need to do is :
- If you are using softdevice, please flash the softdevice prior to the bootloader. When you flash the bootloader, it's better to use nrfjprog.exe
- If you don't plan to use the softdevice, you need to flash the MBR (master boot record) . The MBR is located at \components\softdevice\mbr
If you haven't tried any example in the SDK, I would suggest to get familiar with other examples before starting with the bootloader.
For the bootloader, I have made a tutorial here. It's for Secure bootloader but quite similar to the open bootloader.