Programming custom NRF52832 board using SWD interface

RE: Programming custom NRF52832 board using SWD interface

Simonr — Wed, 24 Mar 2021 09:54:04 GMT

We don't have any details as to what this bootloader is, but I assume Sparkfun provides it in the case that this should happen. You can check out this thread on DevZone for an explanation on how to use a Sparkfun board with a DK. I would also assume that recovering the Sparkfun board would be similar to how you recover the nRF52840 Dongle, which is described in the Dongle Programming tutorial.

As for the board file configuration and GPIO configuration, please check out "The board files" section in part 3 of our NCS tutorial which explains the complete setup of custom board files in NCS, as it is not only the board file deciding GPIO mapping etc. in NCS. It is better explained in that guide than I can do in a single DevZone comment.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Wed, 24 Mar 2021 00:45:25 GMT

Hello Simon,

The reply option is not available for the message you sent me yesterday, so I am replying to a previous message.

I opened the zephyr -> boards -> arm -> nrf52dk_nrf52832, where I have the following files.

1. board.cmake

2. Kconfig

3. Kconfig (board file)

4. Kconfig.deconfig

5. nrf52dk_nrf52832.dts

6. nrf52dk_nrf52832.yaml

7. nrf52dk_nrf52832_deconfig

I checked what was inside the Kconfig, and I DID NOT find any GPIO assignments inside that file, instead I find the GPIO assignments on nrf52dk_nrf52832.dts file.

Please suggest, it is this file that works as the GPIO mapping file?

So, what if I change this file to correspond to the Sparkfun board or my custom board, and start a new project based on the nrf52dk_nrf52832 , which will now pull the GPIO configuration based on the Sparkfun board, would that work?

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

DineshB — Tue, 23 Mar 2021 13:59:31 GMT

Hello Simon,

Is there a way to unbrick the boards through NRFDK SWD interface to a custom board?

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Tue, 23 Mar 2021 11:41:14 GMT

Hi Dinesh

The board files in the nRFConnect SDK can be found as described here, in /zephyr/boards/arm/ folder. It also describes how you can define your own board., and this guide helps you add your own custom board to the Zephyr build system.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Tue, 23 Mar 2021 03:26:14 GMT

Hello Simon,

Could you kindly advise me the location of the NRF52DK board file for the peripheral_uart project? I am using the nRF Connect -> Tool Chain -> IDE and then I open File -> nRF Connect SDK project and choose the project and the hardware (board), in this case NRF52DK_NRF52832.

The sparkfun breakout board's connections are as follows.

1. Reset pin <pin 21>

2. LED pin <pin 07>

3. Push button <pin 06>

4. RX pin <pin 26>

5 Tx pin <pin 27>

All the other pins are left open and are not connected anywhere. What would be the minimum set of requirement on the NRF52DK board, when it is running the peripheral_uart sample project? I believe, it requires Reset pin, LED, push button, serial port (perhaps with RTS/CTS??). My understanding is, that, if I change these pin assignments, then the peripheral_uart app should work on the Sparkfun breakout board as well. So kindly advise me, where I can find this definition file for the nRF Connect SDK projects.

Also, I think when I was trying these options, I BRICKED a couple of my sparkfun boards (where they are not responding through the nrfjtool when I try to erase them and reflash the bootloader) through the NRF52DK SWD port.

Is there a utility / method to get these bricked boards working now?

Your help is much appreciated.

Thanks.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Mon, 22 Mar 2021 08:05:44 GMT

I'm not suggesting to edit the NRF52DK board file, but rather make your own custom board file for your custom board, where the TX/RX pins used in HW are set in this board file. Yes, they are "just" pin assignments, but in our example projects we call these defines so that they are used by the project as well. See the RX_PIN_NUMBER and TX_PIN_NUMBER calls in the UART peripheral example for instance, which are called from the board file used in your project.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Fri, 19 Mar 2021 14:46:52 GMT

Hello Simon,

Are you suggesting, if I go and remap the RX/TX pins from P0.06/P0.08 to P0.27/P0.26, then perhaps I should be able to program the cards, both Sparkfun dev kit and the custom board, through the NRF52_DK board selection?

Also, these are just pin assignments, and if nothing is connected to the rx/tx pins, how would the program know if these pin assignments are wrong? After all, its telling the processor to use 6 and 8, instead of 26 and 27. Is there some form of a communication between the nrf chip and the debug chip, through SWD interface, that will emulate JTAG and make sure the serial port is working (so you would need the correct pin mapping)?

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Fri, 19 Mar 2021 08:46:50 GMT

[quote user="DineshB"]So, on the Sparkfun dev kit, nothing is connected, all GPIOs are open, only the rx/tx are connected to a serial2uart cable. Their definitions are, P0.27 -> TX and P0.26 -> RX[/quote]

I think this is the reason, the Nordic Development Kits use P0.06 and P0.08 for UART by default for instance. It is generally important to select the correct board files for the board you're using. If your custom board is a replica of the Sparkfun board then selecting the sparkfun board should be fine, but we generally suggest creating board files for custom boards.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Thu, 18 Mar 2021 21:30:30 GMT

Hello Simon,

I managed to program the Sparkfun dev board and get it up and running.

What I had to do was to select nrf52_sparkfun as the Board Name, instead of nrf52dk_nrf52832.

nRF Connect -> Tool Chain Manager -> nRF Connect SDK v1.4.2 -> Open IDE

Then I use,

File -> Open nRF Connect SDK project -> fade led (projects) , nrf52_Sparkfun (Board Name) , 1.4.2 (nRF Connect SDK Release), 1.4.2 (nRF connect Tool chain version)

So, on the Sparkfun dev kit, nothing is connected, all GPIOs are open, only the rx/tx are connected to a serial2uart cable. Their definitions are, P0.27 -> TX and P0.26 -> RX

I still don't understand, if the circuit is not connected to any other peripheral, what would be the different settings in terms of selecting the Board (nrf52DK vs nrf52_sparkfun) that makes the board work only when you select the nrf52_sparkfun?

Next, I will try to program my custom board with nrf52_sparkfun as the Board selected. But this still puzzles me, what would prevent the app (uart_peripheral) work only with the nrf52_sparkfun Board selection, instead of the nrf52DK.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Thu, 18 Mar 2021 09:18:11 GMT

1. In the nRF5 SDK you can edit the following defines in the project's sdk_config.h header file to these values to enable the RC oscillator and calibration.

// <h> Clock - SoftDevice clock configuration

//==========================================================
// <o> NRF_SDH_CLOCK_LF_SRC  - SoftDevice clock source.
 
// <0=> NRF_CLOCK_LF_SRC_RC 
// <1=> NRF_CLOCK_LF_SRC_XTAL 
// <2=> NRF_CLOCK_LF_SRC_SYNTH 

#ifndef NRF_SDH_CLOCK_LF_SRC
#define NRF_SDH_CLOCK_LF_SRC 0
#endif

// <o> NRF_SDH_CLOCK_LF_RC_CTIV - SoftDevice calibration timer interval. 
#ifndef NRF_SDH_CLOCK_LF_RC_CTIV
#define NRF_SDH_CLOCK_LF_RC_CTIV 16
#endif

// <o> NRF_SDH_CLOCK_LF_RC_TEMP_CTIV - SoftDevice calibration timer interval under constant temperature. 
// <i> How often (in number of calibration intervals) the RC oscillator shall be calibrated
// <i>  if the temperature has not changed.

#ifndef NRF_SDH_CLOCK_LF_RC_TEMP_CTIV
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2
#endif

// <o> NRF_SDH_CLOCK_LF_ACCURACY  - External clock accuracy used in the LL to compute timing.
 
// <0=> NRF_CLOCK_LF_ACCURACY_250_PPM 
// <1=> NRF_CLOCK_LF_ACCURACY_500_PPM 
// <2=> NRF_CLOCK_LF_ACCURACY_150_PPM 
// <3=> NRF_CLOCK_LF_ACCURACY_100_PPM 
// <4=> NRF_CLOCK_LF_ACCURACY_75_PPM 
// <5=> NRF_CLOCK_LF_ACCURACY_50_PPM 
// <6=> NRF_CLOCK_LF_ACCURACY_30_PPM 
// <7=> NRF_CLOCK_LF_ACCURACY_20_PPM 
// <8=> NRF_CLOCK_LF_ACCURACY_10_PPM 
// <9=> NRF_CLOCK_LF_ACCURACY_5_PPM 
// <10=> NRF_CLOCK_LF_ACCURACY_2_PPM 
// <11=> NRF_CLOCK_LF_ACCURACY_1_PPM 

#ifndef NRF_SDH_CLOCK_LF_ACCURACY
#define NRF_SDH_CLOCK_LF_ACCURACY 1
#endif

2. In NCS, you need to go to the "Configure NCS project" option in the Project dropdown folder in SES and change the Clock control source to use the RC oscillator instead of external crystal.

Please note that if you've followed the sparkfun schematics you should have this external crystal however, so this should not be the issue it seems. Are you able to run the example project on the nRF52 DK?

Are you using the toolchain manager in nRFConnect to set up the nRFConnect SDK, or do you refer to the getting started guide? I would recommend using the toolchain manager for new users, as this is easier to get started with. When opening the SES IDE, how do you open the project. Please note that you should "Open nRFConnect SDK project" in "File" when opening new projects in NCS.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Wed, 17 Mar 2021 20:40:55 GMT

Hello Simon,

I connected the NRF52-DK to the Sparkfun dev kit, as per your instructions. (My custom design is based on the Sparkfun dev kit design). You can check their schematics here,

sparkfun-nrf52832-breakout.sch

Based on their schematics (which is what my current designs are based on), both the 32MHz and 32KHz crystals are connected.

I am using nRF Connect v3.6.1 and nRF Connect SDK v1.4.2 and peripheral_uart project.

Even with this Sparkfun development board, I am unable to get the peripheral_uart project up and running, whereas I have verified that the Sparkfun board is working through a different (Arduino) toolchain/IDE.

Please advise, what could be the problem here. I see that both the crystals are connected. When I BUILD & RUN from the SES, there is no error thrown, and looks like the flashing goes smoothly.

I believe, if I can get this dev kit to work with the SES + peripheral_uart project, then I can simply get my custom hardware to work with the SES + perhipheral_uart as well.

Looking forward to hearing back from you soon.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

DineshB — Wed, 17 Mar 2021 14:21:29 GMT

Hello Simon,

At the moment, I am using NRF5 SDK with NRF52832 device, and the uart_peripheral sample app.

Please kindly advise, where I can find the LF clock definition in ,

1. NRF5 SDK

2. NRFConnect SDK (NCS)

I shall try both the options, and make sure the hardware works fine. Then I can make a choice, based on the features available on each option.

Thank you for your help.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Wed, 17 Mar 2021 13:36:54 GMT

Hi again Dinesh

You're using nRFConnect SDK (NCS), correct? And thus this example project? If you only have the one external crystal that explains why it doesn't start advertising. In order to run most of our examples, you also need to use a LF clock (32.768 kHz), and our example projects are configured to use the optional external (XTAL) 32.768kHz crystal. You can configure the example to use the internal RC oscillator instead though, which should make the application run as intended.

1. NCS does not use the SoftDevices, so it seems like you're mixing up the nRF5 SDK and the nRFConnect SDK.

2. I believe it should be sufficient to configure the project to use the RC oscillator instead of the XTAL. Please see the documentation here for details. The calibration should be enabled by default when the RC oscillator is enabled it seems.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Tue, 16 Mar 2021 19:35:21 GMT

Hello Simnor,

I still struggle with this setup.

I connected the power/GND/SWDIO/SWDCLK as per your suggestion.

When I run the BUILD & RUN from the SES, I can see that the programming is going on.

However, I programmed the unit with the peripheral_uart example, and I expect it to start advertising, and I should be able to use another device with NRF Toolbox -> UART and Connect / Scan , where I expect the unit to pop up with Nordic_UART_Service. But I don't get that.

On the other hand, if I program the NRF52832 on the DK board (by removing my device from the DK), I am able to observe its advertisements with "Nordic_UART_Service".

I believe for this "periphral_uart" example, no external pins are required for it to kick start the advertisement?

And, my NRF custom design has an external Crystal connected to it, which is 32MHz.

Side note, I am able to program a custom bootloader + app on this board, through a set of utilities provided by Sparkfun, The app works fine on this custom board. However, the issue is, the sample app template they have provided and their libs wouldn't let me to obtain the low power levels (around 10 - 20uA) , compared to what your setup seems to support. So I want to use the same hardware and start the development with the SES. Why I am saying this, is to let you know that the custom hardware board is functional (with someone elses tools).

So I need your support to get my custom hardware to run the uart_peripheral and start advertising, where I can pick up the advertisements from another Android device running NRF Toolbox -> UART.

A few questions.

1. Since I already flashed a softdevice + bootloader to these boards (for the sprakfun), does your debugger ignores them and flash the sample app directly and able to run it? (uart_peripheral app from the SES, build and run option)

2. What other additional requirements are needed to run the perhipheral_uart sample, through SES -> BUILD & RUN option?

Looking forward to hearing back from you soon.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Mon, 15 Mar 2021 07:58:57 GMT

Please let me know whether this is successful or not. If you're still struggling, please let me know some details about your custom board. If you're, for example, lacking an external LF crystal that is likely the issue.

Best regards,

Simon

RE: Programming custom NRF52832 board using SWD interface

DineshB — Fri, 12 Mar 2021 17:16:57 GMT

Hello Simonr,

I was powering my custom board separately (through a coin cell battery) and wired the VTG on DK to VDD on my board side (3.3v).

I will remove the power source (coin cell) on my board, and power the custom board through the NRF52-DK as per your suggestion.

I believe, once I execute the BUILD & RUN, the same behavior is expected on my custom board, similar to how it runs on the DK, as on DK, I see the NRF advertisements, but when I programmed my board, I couldn't see the advertisements.

I will test this and get back to you.

Thanks.

regards,

Dinesh.

RE: Programming custom NRF52832 board using SWD interface

Simonr — Fri, 12 Mar 2021 13:49:33 GMT

Hi Dinesh

Please confirm that your custom device is connected as shown in this picture when trying to program it. How is your custom board powered?

1. No, you do not need a bootloader, the debugger on the DK will be able to access the Flash of the nRF52 series through the SWD interface.

2. Yes, when the custom board is connected correctly to the DK, the "Build and Run" command in SES will download the application onto the custom board, as it will detect connected custom boards automatically.

3. In the peripheral_uart example you can see that the RX and TX pin numbers are defined as RX_PIN_NUMBER and TX_PIN_NUMBER. These are defined in the board file (C:\...\nRF5_SDK_17.0.2_d674dde\components\boards\pca10040.h), and when making a project for a custom board, you should create your own custom_board.h file. This is described in the Infocenter here where it is explained how to use the SDK with custom boards.

Best regards,

Simon