nRF52 DK debug out via P19

[RW]

I am in the process of getting some nRF52832 based proto units and plan to use the nRF52 DK to load the code and maybe do some external debugging. I will be using P19 (debug out connector) on the DK.

Couple questions:

1. The proto unit will be on 1.8V power domain, and the nRF52 will be USB powered. Do you know if there is any issue?
2. EXT_VTG = 1.8V, SWDIO and SWDCLK are quite straightforward. What do I need to do with EXT_GND_DETECT, EXT_RESET?
3. For flashing the proto unit only, can I leave SWO signals open?

Thanks,

RW

[butch]

Not an answer, because I am not sure. 1) When I do it, I power the proto from 2 AAA cells, so I don't think the voltage difference matters. 2) and 3) I use 5 lines, the first three you mention, plus GND and EXT_GND_DETECT. I don't connect SWO and never use it (I don't know what it does for you. I use Segger RTT for logging.) I think the connections are discussed elsewhere on this forum.

[Stian Røed Hafskjold]

1. In the user guide for the DK:

Important: The voltage supported by external debugging/programming is 3.0 V.

However, I tried flashing a device that was powered with 1.8V now, and it worked. I can't guarantee that it will always work because of the statement in the user guide.

2. EXT_GND_DETECT should be connected to GND of the external device. And that should be it. VTG, GND, SWDIO and SWDCLK.

3. You don't have to connect the SWO signal.