nRF5340 external clock requirement

RE: nRF5340 external clock requirement

Einar Thorsrud — Tue, 18 Jun 2024 09:17:24 GMT

Hi,

I am glad to hear you got it working. Thanks for letting me know.

RE: nRF5340 external clock requirement

luker — Mon, 17 Jun 2024 22:27:17 GMT

Hi Einar,

Thank you for your help. I didn't realise there had been another course released regarding nRF Connect, I went through it and used the example they provided to copy the DK files and change rename parameters accordingly and have now managed to get the board working.

RE: nRF5340 external clock requirement

Einar Thorsrud — Fri, 07 Jun 2024 09:23:22 GMT

Hi,

Is what you are saying that if you build for nrf5340dk_nrf5340_cpuapp and flash your custom board your simple app or blinky works? But with your own board files it does not?

Have you debugged and observed the log output? What does that tell you? Also, what is thed difference between your board files and the DK board files?

PS: There is a module on custom board files in the nRF Connect SDK Intermediate course: Lesson 3 – Adding custom board support.

RE: nRF5340 external clock requirement

luker — Fri, 07 Jun 2024 04:21:24 GMT

Just a note to this, If I flash the custom board using the nRF5340dk board set as the destination and toggle one of the leds on the custom board it does work. Using the custom build board files it fails to flash the LED, I've been looking into the boot side of things as I don't believe the application is getting to that point of running

RE: nRF5340 external clock requirement

luker — Thu, 06 Jun 2024 23:02:24 GMT

Thank you, glad to hear I can at least get some testing done. I shall create a ticket to get this board and some changes I have already done reviewed for the next revision.

Side note, I was hoping this would explain the issues I'm having with this board but I fear there is more I don't understand regarding project/ board setup to get it to function correctly.

The board does appear to be programmed successfully, just nothing appears to be executing. Currently attempting to just get it to toggle an LED with no success.

RE: nRF5340 external clock requirement

Einar Thorsrud — Thu, 06 Jun 2024 07:31:45 GMT

Hi,

The 32 MHz crystal is needed for anything that requiers a precise clock, for instance the radio. But the MCU starts up using the internal HFINT clock, and the CPU runs of that. So as long as you don't use the radio or try to start the HFXO in any other way, you will be able to use the CPU etc, so you can do some basic testing.

PS: I suggest opening a new support case here to get your schematics and layout reviewed.