SEGGER J-Link debugger/programmer for nRF52840

RE: SEGGER J-Link debugger/programmer for nRF52840

Vidar Berg — Thu, 06 Oct 2022 09:53:12 GMT

Hello,

The problem is that J-Flash Lite sometimes fail to reset the target after loading the FW binary. I reproduced it here, but not sure what the root cause is - maybe it's trying to do a pinreset before it is enabled.. Anyway. for development I suggest you use nrfjprog/west, or the Programmer app in nRF connect for desktop if you want a GUI alternative.

[quote user="IoTMAN"]but I've discovered that .bin files do[/quote]

zephyr.bin and zephyr.hex are linked to the same address. The difference with *.bin files is that they don't contain any address information, so you have to tell the programmer where to load the data (0x0 in this case). For multi-image builds (e.g. application + bootloader), you can use the merged.hex file instead (see https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_multi_image.html#what-are-image-files for a description of the different hex files that may be produced by the build process).

RE: SEGGER J-Link debugger/programmer for nRF52840

IoTMAN — Wed, 05 Oct 2022 16:05:21 GMT

Hello, I'd like to add to rmptxf's answer. This is for when you use P20 for programming and debugging an external device.

1- Use P20 on the board and make the connections he provided, (I will use DK term for the device that has a J-link which will be connected to the external device that will be programmed such as a dongle)(you don't need to power the device if it's a dongle).

2- Build your application for proper device (nrf52840, 52840 dongle, 52833... etc.)

3- go to location <your_workspace_path\your_application_folder\build\zephyr> where we'll need the zephyr.bin and zephyr.hex files.

4- Open J-Flash Lite (I'm using V7.66a version). Choose device to be programmed > click OK > click three dots below the "Data File (bin / hex / ...)....." find the zephyr.bin path located in step 3.

5- Click Program Device

6- Repeat step 4 for zephyr.hex

7- Click Program Device

8- it should work.

You might ask," why do you program .bin and after that the .hex file, wouldn't the .hex just overwrite anyway?" Nope. Although sometimes just flashing the .hex file works, most of the time it did'nt for me and I don't know why. It was a coincidence that I've discovered this. But I'm guessing it's something to do with bootloader. .hex files don't start form address 0x0, but I've discovered that .bin files do. So overwriting them somehow makes it work. Hope it helps. Any technical explanation on why this works is appreciated.

RE: SEGGER J-Link debugger/programmer for nRF52840

Vidar Berg — Tue, 29 Sep 2020 10:10:33 GMT

The target board must have the same VDD voltage as the DK. Otherwise you will need a level shifter. The standalone J-links have one built-in.

RE: SEGGER J-Link debugger/programmer for nRF52840

Muqarrab — Tue, 29 Sep 2020 06:01:49 GMT

Thank rmptxf,

Do I need a level converter? As I have seen some chips have 3.3 operating voltage and some have 1.7-5.5v.

RE: SEGGER J-Link debugger/programmer for nRF52840

rmptxf — Mon, 28 Sep 2020 18:55:31 GMT

Hi Muqarrab,

1- It should work.

You can also use the nRF52840-DK instead. It has an on-board debugger that can also be used to flash and debug firmware on external SOCs.

You just need to connect your external SOC through the debug out port. Once your external SOC is detected, the debugger will switch the connection to it, and ignore the on-board SOC.

If you managed to have an SWD connector on your custom board, that'll be easier. You'll just need a cable to connect them both.

Like in here. The custom board is the Adafruit nRF52840 Feather express.

Or, you can just connect the SWD related pins on the P20 of the nRF52840-DK, to your custom board.

Note: You do need to power your external board.

2- You can just look for the SWD interface pins. That's all you need !

3- You can still use the DK here too. But, if you have lot of devices, I think using an external debugger would be good, with some sort of pogo-pins, and a Tag-Connect footprint on the custom PCB.

Find some tips about that here : https://partsbox.com/blog/choosing-a-debug-programming-connector-2019.html

Hope that helps.

Best regards,