Problem bringing up a custom board (cant see board outside of bootloader mode)

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Mon, 02 May 2022 11:58:25 GMT

About 3.3V should be fine, also with the J-Link EDU Mini.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Sat, 30 Apr 2022 05:22:06 GMT

I measured VDD in both normal and reset modes, and it was 3.3v

Additionally, the SWDIO is 3.3v

I am using the JLink EDU Mini. Could that be why?

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Wed, 27 Apr 2022 08:38:15 GMT

Which type of J-Link debugger are you using? And what VDD voltage to you measure when you hold the device in reset and what do you measure when it is not held in reset? Also, check voltage on SWDIO signals from the nRF?

I ask because if you have a basic J-Link which is fixed to be used with ~3.3V, then you will have problems before you can write to GPREGRET0 so that the high voltage regulator outputs a higher voltage (default is 1.8V).

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Tue, 26 Apr 2022 14:51:01 GMT

I totally agree that it doesn’t make sense to operate in this mode and I know it won’t work. I was just trying to do it because the debugger won’t see the board otherwise. I know that is not the expected behaviour and the jlink should see it when it’s not in reset mode.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Tue, 26 Apr 2022 11:53:25 GMT

Hi,

I am sorry to say, but there is nothing here that rings any bells. Other than that I still struggle with this:

[quote user="hmahdi"]but of course I cant actually debug because jlink still only sees the board when the reset switch is flipped[/quote]

If the reset pin is enabled and reset is asserted the device is in an undefined state, so nothing and anything could happen. So there is no point in operating in this condition (if that is what you mean).

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Mon, 25 Apr 2022 23:51:23 GMT

I have some more information about the error. When I use the "recover board" feature in vscode, I can see the board when not in reset mode as long as I have not downloaded any code to the board. So what I did, I clicked debug on this clean board, and I got a new error message:

Program
 received signal SIGTRAP, Trace/breakpoint trap.
0xdeadbeee in ?? ()
Debug-14: Enqueuing {"command":"disassemble","arguments":{"memoryReference":"0xdeadbeee","offset":0,"instructionOffset":-200,"instructionCount":400,"resolveSymbols":true},"type":"request","seq":14}
Note: We detected the following memory regions as valid using gdb "info mem" and "objdump -h"
    This information is used to adjust bounds only when normal disassembly fails.
================================================================================
  Using following memory regions for disassembly
================================================================================
      Size   VMA Beg   VMA End   LMA Beg   LMA End  Attributes
================================================================================
  Unfortunately, No memory information from gdb (or gdb-server). Will try to manage without
  ------------------------------------------------------------------------------
  0000503c  00000000  0000503c  --------  --------  (.sec1) contents alloc load
================================================================================
Debug-14: Dequeuing...
Debug: Gdb command: -data-disassemble -s 0xdeadbbce -e 0xdeadc20e -- 5     1600 bytes 
Error: GDB failed: Cannot access memory at address 0xdeadbbce (from data-disassemble -s 0xdeadbbce -e 0xdeadc20e -- 5)

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Mon, 25 Apr 2022 23:42:39 GMT

Thanks for your patience we me. I remade the board with the vscode extension this time (not starting from the dk or the dongle) to back track even more.

It seems this is definetly on the right track, because I no longer get a SIGTRAP when running debug (but of course I cant actually debug because jlink still only sees the board when the reset switch is flipped).

Here is a screenshot of when I run debug in reset mode:

P.S. I did what you suggested by essentially only adding the one pin needed by the blinky program for the sake of simplicity.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Mon, 25 Apr 2022 10:16:27 GMT

Hi,

Can you backtrack and continue to test with the Blinky example first, and use a board based on nrf452840dk_nrf52840 (not the dongle!)? Even if you have a dongle form factor, the nrf452840dk_nrf52840 is likely a better starting point as it has no fuzz. Then it should be enough to only change the LED pin to get the blinky sample working.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Sat, 23 Apr 2022 18:39:12 GMT

Unfortunately, connecting the reset pin did not change the behaviour.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Thu, 21 Apr 2022 00:55:15 GMT

I found this person saying the reset pin could solve the problem. I will try to connect the reset to the jlink:

https://devzone.nordicsemi.com/f/nordic-q-a/82547/cant-program-custom-board

I'll keep you posted. Meanwhile, if it seems anything is wrong with the configuration i posted please let me know!

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Wed, 20 Apr 2022 23:16:49 GMT

That is what I thought, however, I also tried to use the ftsab-debugger configuration which starts at

0x000000000 :

&flash0 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		/* The size of this partition ensures that MCUBoot can be built
		 * with an RTT console, CDC ACM support, and w/o optimizations.
		 */
		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x000000000 0x00012000>;
		};

		slot0_partition: partition@12000 {
			label = "image-0";
			reg = <0x00012000 0x000069000>;
		};
		slot1_partition: partition@7b000 {
			label = "image-1";
			reg = <0x0007b000 0x000069000>;
		};
		scratch_partition: partition@e4000 {
			label = "image-scratch";
			reg = <0x000e4000 0x00018000>;
		};
		storage_partition: partition@fc000 {
			label = "storage";
			reg = <0x000fc000 0x00004000>;
		};
	};
};

It did not change the behaviour. I made sure to remove BOARD_HAS_NRF5_BOOTLOADER

Sorry for asking too many questions but it's frustrating because I know the debugger sees the microcontroller but i am getting literally nothing. I dont think it's a hardware issue so most likely, it's the board configuration.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Tue, 19 Apr 2022 07:46:29 GMT

I think it is time to backtrack a bit. As I explained in my previous post, you have configured your board to build the application starting at 0x1000, as if it has the nRF5 SDK bootloader (which is the case for the nRF52840 dongle). If that is not intentional, the solution should not be to add the bootloader (which is a different bootloader than what you find in the nRF Connect SDK), but rather change your board configuration to remove that part so that you don not rely on the nRF5 SDK bootloader. (That is used in the nRF52840 dongle for legacy reasons and I see little reason for wanting to put that in a dongle you make).

So, instead, I suggest you change your Kconfig.defconfig and remove BOARD_HAS_NRF5_BOOTLOADER etc.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Sat, 16 Apr 2022 19:23:49 GMT

Ok as a follow up, I attempted to install the bootloader example from the nrf Connect SDK, however, that did not change the behaviour of the microcontroller and did not solve the problem. I also tried on the blinky example itself by setting CONFIG_IS_SECURE_BOOTLOADER=y in the config.

I am quite lost and not sure how to get the bootloader on the microcontroller correctly.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Sat, 09 Apr 2022 20:38:21 GMT

Thanks Einar this is really valuable information. I actually did not flash any bootloader as I do not have much embedded development experience and I didnt know the chips dont come with it. I will flash the nRF5 SDK bootloader to stay as close to the dongle as possible.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Fri, 08 Apr 2022 14:09:41 GMT

Hi,

I do not see anything sticking out in your dts.

I just remember one thing though, and checking that I see an issue. In your Kconfig and Kconfig.defconfig you have BOARD_HAS_NRF5_BOOTLOADER and FLASH_LOAD_OFFSET etc. This is inherited from the nRF52840dongle_nrf52840, and is becaue this dongle ships with a nRF5 SDK bootloader, where the first page is the MBR. As you write that you see the board in bootlaoder mode I assume you flashed the nRF5 SDK bootloader on your custom board as well? If not (for instance you are using another bootlaoder, like MCUBoot), this is not correct and should be removed. It is generally only sensible for the nrf52840 dongle, and not other (though similar) boards.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Thu, 07 Apr 2022 18:20:09 GMT

I have not modified the blinky program at all. It should work because I created an LED with the same alias in the device tree. Here is the .dts file which I think is most relevant from the board defintion so it's simpler to sift through.

devzone.nordicsemi.com/.../nrf52840hab_5F00_nrf52840.dts

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Thu, 07 Apr 2022 08:45:24 GMT

Ah, so you mean that you can "debug" when reset is asserted (held low)? At that point the CPU is not running, though (and in fact most of the IC is in an undefined state while the reset pin is asserted).

[quote user="hmahdi"]I am using the base blinky program. I wonder there is a hard fault. [/quote]

Yes, it looks like it. Can you upload the full project including any modifications you have done so that I can take a look (in your previous upload I saw the board file etc but not the blinky project etc)? It could also make sense to remove your board specific code just for simplicity to try to narrow down the issue.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Tue, 05 Apr 2022 15:23:32 GMT

By reset mode I meant flipping the nreset pin which can be seen on our schematic. I attached a screenshot highlighting it.

I am using the base blinky program. I wonder there is a hard fault. Maybe it’s the board configuration but I’m pretty sure I left most aliases the same so it would be compatible with the demo blinky out of the box ( ex: left led 0 with the same name but changed the pin to match our board)

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Tue, 05 Apr 2022 07:29:05 GMT

Can you elaborate by what you mean by chip being in "reset mode"? Anyway, looking at the screenshot it looks like you are able to debug, and you get a SIGTRAP at 0xFFFFFFFE, which indicates you gat a hard fault for some reason.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Tue, 05 Apr 2022 01:24:29 GMT

Thanks @Einar Thorsrud.

1. I attached the schematics as well as the custom board I defined withing nrf connect sdk. It was modified from the nrf52840 dongle board definition.

2. In terms of debugging, I am in a conundrum because the debugger only sees the board in reset mode. I attached the output.

Additionally, I tried the code on a fresh board. I noticed that prior to installing any code, I can see the chip through the debugger whether the chip is in reset mode or not. However, after flashing the blinky program (which still doesnt work), I noticed the debugger can only see the chip when it's in reset mode.

devzone.nordicsemi.com/.../8463.MCU_5F00_Schematic.pdf devzone.nordicsemi.com/.../nrf52840hab_5F00_nrf52840.zip

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Mon, 04 Apr 2022 07:42:52 GMT

I see. So Blinky is also not working. Please continue testing with Blinky, as that is the simplest possible example application and that really should work. As it does not, something is fundamentally wrong.

Can you upload your schematics and layout, and also your Blinky project (with any modifications you have made for your board). That way I can review to see if I see something obvious.
Let me know whatever you find from attempting to debug? What exactly happens? Can you share logs, screenshots, etc, to make tit clearer?

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Sun, 03 Apr 2022 23:03:08 GMT

I have tried a Blinky example, and it compiles fine with the custom board that i have defined, however, i dont see the voltage changing on the pin at all. I also tried this: https://devzone.nordicsemi.com/f/nordic-q-a/77570/zephyr-project-on-a-custom-board-wont-start-up-after-removing-debugger

But it did not seem to work for me.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Tue, 29 Mar 2022 12:10:52 GMT

Have you got debugging working? I wrote about bootloader, but please keep that out of things. No need to complicate more then necessary, so don't use a bootloader at first.

Can you start by just trying to flash the Blinky sample and observe that it toggles the pin (you don't even need a LED on it, just check it with a logic analyzer if hat is easier). Next step is to debug. Are you able to debug? Then gradually move on.

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

hmahdi — Mon, 28 Mar 2022 16:13:09 GMT

Sorry for my late reply. I tried to get a GPIO to output a high but nothing is happening. I tried the same program on a dongle and it worked.

Here is the schematic of the custom board:

devzone.nordicsemi.com/.../MCU_5F00_Schematic.pdf

RE: Problem bringing up a custom board (cant see board outside of bootloader mode)

Einar Thorsrud — Fri, 25 Mar 2022 08:59:45 GMT

Hi,

[quote user=""]I have designed a custom board for the nrf52840 and upon testing it in the nrf connect sdk (using a JLink), I can only see the board when it's in () mode. When it's in normal operation, the debugger does not show it. [/quote]

If the debugger is connected, then you should always see it. Can you explain a bit both how you test, how your firmware is and how your HW is.

[quote user=""]Additionally, it does not appear as a USB device although I enabled USB CDC. In fact, I kept the configuration pretty much similar to the nrf52840 dongle when I defined the custom board on the nrf connect sdk.[/quote]

Difficult to say here. Bu tif you are not even able to debug, there could be a more fundamental issue. I think you need to get the basics working first.

Could it for instance be that you have connected the debug (SWD) lines to a GPIO that you force high or low from your application? (that is just a wild guess, we need more information to make more precise suggestions).