External Segger J-Link™ Debug Interface
External target hardware, such as a custom PCB, can be connected to J3 for firmware programming and debug. The Segger debug interface is implemented as shown in Figure 15. J3 is implemented with a 2x5 10-pin header on 0.05” centers.
In order to enable the external J-Link connection on the Eval boards, ensure the following are implemented on the target hardware:
- EXT VTG (3.0V - 3.3V operation ONLY)
- Used by the debug interface as an input. Connect EXT VTG to the BMD-300 Series power supply (VCC) on the target hardware.
- If your target design does not operate at 3.0V-3.3V, then an external Segger J-Link interface is required to prevent damage to the target module. The Base model is sufficient.
- EXT GND DETECT
- Detect the presence of external target hardware. Connect EXT GND DETECT to GND on the target hardware in order to program the external hardware rather than the on-board module.
- EXT_SWDIO and EXT_SWCLK
- Connect to SWDIO and SWDCLK on the target BMD-300, respectively.
- EXT_SWO, EXT_RESETn (Optional)
- Connect to P0.18 and P0.21 on the target BMD-300, respectively.
Connect external power to the target hardware, then connect the BMD-300 Series Evaluation Board to USB. At this point, the debug interface will interact with the target hardware instead of the on-board BMD-300.
These may come in handy for programming:
- SWD programming cable: https://www.adafruit.com/products/1675
- SWD break-out board: https://www.adafruit.com/product/2743
The BMD-300-EVAL Segger code is provided by Nordic. Segger provided a special license to allow Nordic's partners to use the code as-is for evaluation boards. It is against the license to use the BMD-300-EVAL to program production devices.
Comments
6 comments
For an external board, is a bmd 300 module and the above pins all you need to create a simple beacon? No crystals or any other components needed?
Correct.
When using the Eval board to program an external BMD-300, VCC is required. The EXT_VTG pin above is an input to the debugger and does not supply power to the target module.
Note that the examples provided by the Nordic SDK assume an external crystal. Be sure to modify the examples to enable the internal RC oscillator instead:
https://rigado.zendesk.com/hc/en-us/articles/225674668-Example-files-will-not-run-on-my-hardware-but-do-on-the-Eval-board-
Thanks, Bob. I have successfully programmed a working ibeacon application. There is a note in this post that says it is against the license to use the eval kit to program production devices? How would you reccomend to program them as production device then?
An external Segger programmer is recommended: www.segger.com
The J-Link base is similar to the J-Link-OB on the eval boards. The J-Link Flash can be set up for "one button" programming without a host PC.
Is there a way to program multiple BMD 300 with say incremeting Major and/or Minor? Or is the only way to production run these one at a time?
If your beacon data is permanent, then you can use the UICR to store that data. A J-Link script can then be used to read a file and send the unique data to each device. See the scripts that are part of the "programmers" repository on GitHub (https://github.com/rigado/programmers - be sure to login to GitHub first). These scripts are what we use to load the factory firmware. You can see where we read the MAC address from a file. You could do something similar with the beacon data.
You would need a separate J-Link interface for each simultaneous device you want to program. Please see the Segger website for documentation and support of J-Link scripting.
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