NRF52832 (on BMD-350 Module) SWD not connecting...

[GJChristman]

I'm having no luck in getting JLinkExe or nrfjprog to see my BMD-350 device on my custom PCB. 

I have read though all the threads here that reference similar issues and have verified all of the following:

* Connections to SWCLK and SWDIO are made properly and have no pullup/pulldown resistors.

* The device is remotely powered

* The signals on SWCLK and SWDIO are there and look to be the proper levels.

* The device itself works - it has factory firmware that advertises services (RigDFU etc.) on BLE

I have tried both a Segger JLink as well as the using the development board programmer via the 10

pin connector.

There has to be something basic I am missing.  Below are a
PDF of the device schematic and the log.log output from nrfjprog -f nrf52 --recover

I'm doing the development in Linux, and have had no problem in connecting to the development board.

I've also asked for help from the manufacturer, UBlox, but have heard nothing back from them.

Any pointers here would be greatly appreciated.

-Glenn

6648.log.logSG_Bluetooth_4-Layer.pdf

[GJChristman]

Yes, Those are the proper colors - signal mappings. 

On the 10-pin connector, 3,5 and 9 are all tied to ground.

[Jared]

Hi Glenn,

GJChristman said:

I re-double-checked the SWCLK and SWDIO and verified that they were going to the appropriate places.  Just to be totally sure, I swapped them anyway and ended up with the same results.  I then swapped them back to the original connections.

I put a scope on the SWCLK and SWDIO lines and again verified that I had 0 to ~= 3.3V signals when issuing commands from nrfjprog or JLinkExe.  The fact that I get appropriate level signals would seem to indicate that they are indeed being connected to the BMD-350, since the pull-up resistors are on the chip.

I also verified that SWO was not connected to GROUND (see my other reply).

Is there any chance that you could try to use a standalone debugger and connect it directly to the modules SWD interface without using the breadboard in-between? I just want to rule out any chance of the breadboard affecting the debugging process in some strange way. 

GJChristman said:

I'm going to build up another board or two and try those.

Ok, it would be great if you could do that. The issue might be related to the module itself. 

keep me updated,

regards

Jared 

[GJChristman]

OK,

I was able to connect to and program the board that has just the BMD-350 and VDD caps - so progress - whoo-hoo!

This at least verifies the SWD connections and interface.  I'll try adding support components to this board and see if I can get it to fail.  It's possible that there is still an issue of getting the BMD-350 properly soldered even though the ones I had pulled off looked pretty good..

I appreciate all your help, Jared et al!

-Glenn

[Jared]

Hi Glenn,

Ok, good to see some progress on this. What exactly is the difference though? Did you remove the regulator stage or the breadboard?

regards

Jared 

[GJChristman]

I built up a target board that had only the BMD-350 and the two caps on the 3.3V line.  The interface board (breadboard) was unchanged.