nrf51 DK board not detected !

[Bhuvanchandra DV]

Hi

Recently we bought NRF51 DK board. Initially when i connect the nrf51 DK board to PC via USB it mounts JLINK driver and on IF/BOOT button it mounts BOOTLOADER drive. Updated the bootloader firmware 'ble_default_bootloader_app.hex' (initial FOTA image: developer.mbed.org/.../ to BOOTLOADER drive. After this i was not able to see the LD5 led blinking/on, and not able to detect the nrf51 DK board as USB device/MSD, tested with nrfGo studio and with JLink tools also. How to recover the bootloader and detect the nrf51 DK board?

[Susheel Nuguru]

I think you flashed the wrong bootloader, try to recover your device using

nrfjprog --recover option

or Run JLink Commander ( JLink.exe ) and in it's command window give following commands; si 1 r h w4 4001e504 2 w4 4001e50C 1 w4 4001e514 1 r That reset's whole flash

[Bhuvanchandra DV]

Thanks for your quick response!

nrfjprog --recover option I don't know where to get this tool

or Run JLink Commander ( JLink.exe ) and in it's command window give following commands; si 1 r h w4 4001e504 2 w4 4001e50C 1 w4 4001e514 1 r That reset's whole flash hmm... i tried that from my linux machine running Fedora21 and form windows machine running Win 8. Running JLinkExe: |dvb|./JLinkExe
SEGGER J-Link Commander V4.98b ('?' for help) Compiled Apr 10 2015 20:27:38 Can not connect to J-Link via USB. J-Link>si 1 r h w4 4001e504 2 Selecting SWD as current target interface. Setting target interface speed to 1MHz. Use "Speed" to change. J-Link>w4 4001e50C 1 Writing 00000001 -> 4001E50C J-Link>w4 4001e514 1 Writing 00000001 -> 4001E514 J-Link>r Reset delay: 0 ms Reset type UNKNOWN: ??? J-Link>

I was expecting a device shown in lsusb or in the device manager. The nrf51 dk board was not at all getting detected as USB device. To use the JLink* tools i think we will need the device to be detected on USB first!

[Susheel Nuguru]

nrfjprog is a nordic tool and you should be able to download in in the nordic product page. Seems like Jlink.exe managed to do what it is needed to erase the whole flash. Can you just reset your device and see if that worked, else nrfjprog is the only possible savior.

[Bhuvanchandra DV]

Hi Aryan,

I believe that there is an issue with J-Link OB, until and unless the board gets detected on USB bus, we cannot do anything(flashing)! Can you please help us to solve the issue with the seeger J-Link OB

-- Bhuvan

[Susheel Nuguru]

Hi Bhuvanchandra, try to connect the board with another PC for testing Also check if this helps. If both the nrfjprog and jlink.exe fail to execute then i think you have bricked your device and it is difficult to bring it up unless you use external jlink module and connect it to SWDIO pin and send the reset sequence manually