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

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

Jared — Fri, 12 Aug 2022 08:14:27 GMT

I see,

[quote user="GJChristman"]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..[/quote]

Keep me updated then,

regards

Jared

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

GJChristman — Thu, 11 Aug 2022 10:36:01 GMT

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.

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

Jared — Thu, 11 Aug 2022 10:17:21 GMT

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

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

GJChristman — Wed, 10 Aug 2022 15:31:29 GMT

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

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

Jared — Tue, 09 Aug 2022 13:26:28 GMT

Hi Glenn,

[quote user="GJChristman"]

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).

[/quote]

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.

[quote user="GJChristman"]I'm going to build up another board or two and try those.[/quote]

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

keep me updated,

regards

Jared

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

GJChristman — Tue, 09 Aug 2022 08:13:12 GMT

Yes, Those are the proper colors - signal mappings.

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

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

hmolesworth — Mon, 08 Aug 2022 23:27:17 GMT

Quite sure about the colours? I see from the photo:

White 1 VDD
Yellow 2 SWDIO
Red 3 nRESET
Blue 4 SWCLK
Black 5 GND
(n/c) 6 SWO

TC2030-IDC-NL-Datasheet-Rev-B.pdf

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

GJChristman — Mon, 08 Aug 2022 23:12:20 GMT

Just to share the misery, here are photos of what I've been talking about:

The whole setup:

The interface breadboard:

and the target...(yellow wire is scope connection on SWDIO)

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

GJChristman — Mon, 08 Aug 2022 23:04:15 GMT

No joy 😞

I pulled R7 and was able to lift a trace to disconnect the OP-AMP - neither seemed to have any effect.

Stubborn little bugger.

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

GJChristman — Mon, 08 Aug 2022 22:47:27 GMT

Interesting thoughts. Yes, the OP-AMP is powered. I can just pull that, and pull R7 as well as a test.

The OP-AMP is going to have an output voltage as well, seeing as the bridge circuit is not complete.

Thanks again.

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

hmolesworth — Mon, 08 Aug 2022 22:32:17 GMT

Idle thought: Try disconnecting Batt_Sense. It will phantom power the BMD350 and prevent the hardware reset functioning properly (internal reset, not pin reset) on power up/down. The reason is the slow startup of the LDOs driving the load capacitance so VCC comes up after io pin has powered the die via internal schottky protection diodes.. as little as 1uA can do this ..

.. also does the op-amp have its power rails connected?

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

GJChristman — Mon, 08 Aug 2022 22:18:10 GMT

Aye, I have the GND_DETECT and VCC lines connected. When I just connect to the Dev_Kit, the tools work fine. In fact, I just erased some test code I had loaded on the Dev_Kit because I didn't have the target board powered up. When all the connections are there the tools refuse to talk to the target board.

I've tried a JLink and gotten the same results.

It's got to be something stupid I'm missing - some pin that I've connected improperly or something.

The Dev_Kit is the Ublox BMD-350-EVAL - pretty much the same as the Rigol or regular Nordic DK from what I can tell - same 10 pin connector and such.

Thanks for the suggestions :)

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

GJChristman — Mon, 08 Aug 2022 22:09:42 GMT

Jared,

Sorry it took me a bit to get back to you today - other work intruded.

Here's where I'm at.

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

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

Here's a shot of the scope just because it's handy - SWCLK on the bottom, SWDIO on top. There's a little noise on the DIO line I see at the start of the pulse. Certainly might be getting a little crosstalk between that and the SWCLK. I didn't do anything special with the wires between the device and the perfboard.

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

hmolesworth — Mon, 08 Aug 2022 21:59:57 GMT

Not clear which development board though assuming the usual 10-pin connector note the development boar requires a GND_DETECT and VCC detect to be able to program, though without those the dev board itself gets programmed; J-Link also needs both Gnd and VCC.. Maybe port the connection details end-to-end, not sure how else to help.

If it happens to be a Rev 3 nRF52832 inside the BMD-350 there is the issue of Approtect but the command-line tool should be able to handle that.

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

GJChristman — Mon, 08 Aug 2022 21:38:46 GMT

Hmolesworth,

A good point.

Although it looks like the SWO pin is connected to ground, there is no connection of that pin to either the BMD-350 or the programmer.

To describe my setup more fully: I have a breadboard in between my device and the Development kit. This board has a header which the TC2030 cable plugs onto, and then wires that go from that header to a 10-pin header connector that plugs into the Development kit. It also has a 3.3V regulator that powers my custom board. The other end of the TC2030 connects to my custom board:

Dev_Kit (10 pin connector)----------------Breadboard------(TC2030)------------Target Board

Power Supply

I have no connection to the Dev_Kit's SWO pin.

When I double-checked, I did notice a short between the TDI pin and the nRESET pin. Even though that pin does not seem to be implemented, I removed that short - but no joy.

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

hmolesworth — Mon, 08 Aug 2022 16:01:05 GMT

Connecting pin 6 (SWO) of the Tag-Connect to Gnd is unusual, although may be benign; maybe try disconnecting that pin

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

Jared — Mon, 08 Aug 2022 09:10:33 GMT

[quote user="GJChristman"]

'm using the Development kit - BMD-350-EVAL to be specific.

Switching to a Windows machine would be difficult at the moment.

I can say that both JLinkExe and nrfjprog - (as well as the Nordic Programmer Linux app) all work when the target is the module on the board itself. (see attached outputs below).

[/quote]

Fair point.

Have you double checked that SWDCLK and SWDIO hasn't been switched when they were routed out on your custom board?

It should be fairly straightforward to flash a board with a debugger.

SWDIO and SWDCLK needs to be connected to their respective pins.
Boards needs to be supplied.
VDD of the board needs to be routed to the debugger.

regards

Jared

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

GJChristman — Fri, 05 Aug 2022 13:50:50 GMT

I'm using the Development kit - BMD-350-EVAL to be specific.

Switching to a Windows machine would be difficult at the moment.

I can say that both JLinkExe and nrfjprog - (as well as the Nordic Programmer Linux app) all work when the target is the module on the board itself. (see attached outputs below).

I would think that if it's a driver issue that wouldn't work either.

I also have had no issues programming the Devkit board from Visual Studio.

-Glenndevzone.nordicsemi.com/.../nrfjprog_5F00_good_5F00_out.txt devzone.nordicsemi.com/.../JLinkExe_5F00_good_5F00_out.txt

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

Jared — Fri, 05 Aug 2022 13:20:43 GMT

Hi,

What kind of debugger did you use when you provided that log? The debugger on the devkit or the stand alone debugger? If the latter, which model?

The error message indicates that the computer isn't able to get in contact with the debugger. Are you able to get in contact with it if you use J-link Commander? The issue might be related to the drivers installed, can you check if changing computer and OS to Windows mitigates the issue?

regards
Jared

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

GJChristman — Fri, 05 Aug 2022 11:52:06 GMT

Hi Jared,

Thanks for responding.

- The voltages on the board are:

* VDD - 3.28V

* GND - .009V

* nRESET - 3.28V

Under test, I am powering the board over the SWD cable with a bench power supply into a 3.3V regulator.

I've tried a couple of the BMD-350s, and they all seem to give the same results

One thing I noticed when looking at a couple schematics I found for the Thingy devices is that you use a 4.6 uF capacitor after the regulator - I have just a 1uF on my board. I was going to try putting a 4.7uF in its place but have not yet done so.

I've attached the output from nrfjprog --recover:

devzone.nordicsemi.com/.../nrfjprog_5F00_out.txt

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

Jared — Fri, 05 Aug 2022 08:53:29 GMT

Hi there,

The schematics looks ok.

Exactly what voltage do you measure on VDD, GND and RESET pin?
Have you tried omitting the regulator stage and power the board directly from a bench top supply?
Do you see this issue on all of your samples?
Thank you for including the log from nrfjprog --recover. But could you also specify what error message that is reported by the program when you just run nrfjprog --recover?

regards

Jared