NRF52840 WLCSP CKAA Problems on program from Segger.

[decastro_25]

Hi folks,

I need of your help. I've developed a new custom board with the nrf52840 CKAA ball assignment and I'm having problems on programming it.

I've developed my code, as the mayority of yours, with the nrf52840 DK. Next, I produced an a first hardware prototype with the QIAA ball assignment, and I debug it with the sam DK board, and it works.

Right now, I'm testing the version 2 with the CKAA, I've supposed that it will works in the same way that the board before, but it doesn't happen. When I connect the SWD wire, the segger  Studio is able to download the code on the board, otherwise, the board doesn't work as it should do.

The case study, it's easy, I want to toggle a led in P0.13 GPIO, as in the DK board Led 1, but my own board doesn't do that it going crazy; I upload a video about what I mean.

So, I was checking the datasheet of the nrf52840, and in the Hardware part, I could appreciate that the assignment ball name in QIAA and CKAA it's different, as I supposed. In the QIAA, the number is AD8, and in the CKAA is H7 for the same GPIO, P0.13.

I've the hope that the Segger Studio will change by own the hardware encapsulated but It doesn't do and I don't know how.

So, has anyone any idea to how can I program the nrf52840 with CKAA ball assignment??

Best regards,

Jorge,

[Nguyen Hoan Hoang]

you're lucky to be able to program it.  Looks like you have quite a few pins shorted together

[decastro_25]

I'm not agree, because I was checking the pins one by one if they're shorted with the closest one, and it's open.

I think that the problem is on the compiler, I should change something on Segger Studio for that processor but I don't know what. 

[Nguyen Hoan Hoang]

If I am not mistaken, you said the code works on other board but not this one.  What see on the video is that multiple led turns on and off at the same time which suggest a short.  With CSP package, the probability of that is high.

CSP or QFN make no difference for software. So based on what you reported, it is unlikely be software issue but hardware problem it is

[decastro_25]

I found the error!! I've tried to download a hello world example from Nordic, and it works!

I was checking my code and its on the clock frequency section, during the test I reconfigured some parameter and for that reason it doesn't work.

I attach a video!!