jlink cannot recognize nrf51-dk

[chadrick]

OS: Windows 10

Target: nRF51-DK

Tried to connect with nrf51-dk with Keil MDK-Lite v5.18a. The default Jlink version used along with this IDE was v4.98e

1. the 'download' button in Keil gave me 'No JLink Device found'.
2. manually executed JLink.exe v4.98e, but it gives "No emulators connected via USB".
3. went to nRF51822 'download' page and download & installed "nRF5x-Command-Line-Tools-Win32" (www.nordicsemi.com/.../39022627)
4. the JLink from (3) is v5.10m
5. again, even JLink.exe v5.10m gives "No emulators connected via USB"

I believe that the fundmental problem is that JLink can't recognize the nRF51-DK connected via usb cable.

However, the nRF51-DK does show up as "MBED"

I would appreciate any useful solution approaches to at least make the JLink recognize the usb-connected nRF51-DK.

[Christopher]

For your information, you can install the latest Segger tools by yourself. The latest version is 5.12. You can download it from here.

You can run JLinkConfig to see the connected Segger probes. You can update the firmware of the emulator if you do not want to use the CMSIS DAP interface.

[chadrick]

solved it. The core of the problem was that the interface firmware(IF) is MBED version, and not JLINK OB version.

Even in the User Guide, it mentioned this but I didn't understand it then but now I do.

From my 'basic' understanding, MBED IF is for loading nRF51 chip with hex files generated from mbed online compiler.

On the other hand, JLINK IF is required for the nRF51-DK to be compatible with J-Link software.

To summarize, the problem had nothing to do with host OS but rather the target board didn't have the proper firmware to interact with JLink tool.

The method of changing the IF is introduced in the "nRF51-DK User's Guide", but the description was not accurate, leading me to do stupid stuff for a long time.

A more straightforward and clear description of do this can be found in one of the answer(answer by Tanasis!) in this post(https://devzone.nordicsemi.com/question/44531/i-cant-update-the-j-link-ob-firmware-nrf51-dk/).

also, I've made a video just in case people would like a more elaborate, straightforward explanation(https://www.youtube.com/watch?v=_z-l-QunYfA&feature=youtu.be)

[Anders Strand]

Thanks for posting an accurate description of the solution :) The main difference between the mBed and JLINK firmware, is that mBed uses CMSIS-DAP between the PC and debugger chip. The JLink uses Jlink. You can drag and drop .hex files on both types.