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?

[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!