nRF52840 DK Switching Shield Debug (P20)

RE: nRF52840 DK Switching Shield Debug (P20)

Einar Thorsrud — Wed, 24 Feb 2021 08:26:50 GMT

Hi,

[quote user="dbeckwith"]So if GND_DETECT is pulled low then those SH_SWDIO and SH_SWDCLK are used?[/quote]

Yes, that is correct.

[quote user="dbeckwith"]Does SH_VTG also need to have voltage on it for those pins to work?[/quote]

Yes, SH_VTG should be connected to VDD on the external board/shield. I assume the board is powered from elsewhere, if not you also need to connect the same point to VDD on the DK. (That also reminds me to mention that unless there is another connecting ensuring a common ground, then you need to connect SH_GND_DETECT to GND on the DK as well.)

RE: nRF52840 DK Switching Shield Debug (P20)

WestCoastDaz — Tue, 23 Feb 2021 19:44:25 GMT

So if GND_DETECT is pulled low then those SH_SWDIO and SH_SWDCLK are used? Does SH_VTG also need to have voltage on it for those pins to work?

Thanks,

RE: nRF52840 DK Switching Shield Debug (P20)

Einar Thorsrud — Fri, 19 Feb 2021 13:36:04 GMT

Hi,

The P20 header is there so that you can debug an external device (like a shield). The purpose of the GND_DETECT is so that the onboard debugger can know if it should use the pins connected to the onboard nRF5 device, or it it should use the pins on the P20 and debug out port instead. See Debug output.