Undocumented SB32 on latest nRF52832 DK

[Marius Heil]

Hello,

I have noticed that there is a SB32 on the newer nRF52 DK boards (PCB 1.2.1), right next to the debug connector. It looks like this is a reference voltage that is directly applied on the Cortex Debug Connector on Pin 1. If I solder this bridge, will it be possible to flash external modules that are not supplied with voltage? Will this stop the nRF52 DK from detecting the reference voltage on the external board and will it always program the external board instead of accidentially flashing the onboard module?

Thanks, Marius

[Bjørn Kvaale]

If SB32 is shorted, then you can supply an external board via the programming pins. Once the SB32 is shorted, it's not possible to program the onboard nrf52832 because Segger routes the SWD signals to the connector (EXT_VTG is used to decide what should get programmed)

[Marius Heil]

Sorry, looks like I wasn't specific enough, I mean the nRF52832 DK infocenter.nordicsemi.com/index.jsp But it's not documented

[Bjørn Kvaale]

But the link you just sent me was for the nrf52840 preview dev kit. I looked at the hardware drawings for the nrf52832 dk, but could not find the SB32. Could you send me a picture of your dev kit with the sb32? It seems weird that they would forget to mention the sb32 in the infocenter.

[Marius Heil]

added picture, its a new revision, documentation is old it seems

[Marius Heil]

Thanks, that was just what I was looking for. I also found out that the other debug headers on the board can be used as well. :-)