Getting Started with NCS (NRF Connect SDK) with simple PWMs.

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Fri, 04 Feb 2022 11:10:24 GMT

Glad that it worked 🙂

-Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Fri, 04 Feb 2022 10:03:36 GMT

I managed to make things work. I finally found a synthax that work with the overlay :

/ {
    pwmleds { 

        pwm_led1: pwm_led1 {
            pwms = <&pwm0 14>;
            status = "okay";
        };
        pwm_led2: pwm_led2 {
            pwms = <&pwm0 15>;
            status = "okay";
        };
    };

    aliases {
        pwm-led0 = &pwm_led0;
        pwm-led1 = &pwm_led1;
        pwm-led2 = &pwm_led2;
    };
};

&pwm0 {
    status = "okay";
    ch0-pin = <13>;
    ch0-inverted;
    ch1-pin = <14>;
    ch1-inverted;
    ch2-pin = <15>;
    ch2-inverted;
};

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Fri, 04 Feb 2022 09:59:07 GMT

Could you create the folder "projects" inside the c:\Users\user\ncs ?

Then, when you open the VS Code via Toolchain manager, click on "Create a new application from sample" and enter the details similar to as follows (your Application location will be c:\Users\user\ncs\projects)

And, later when generating the build configurations, do not enable the debug options.

Regards,

Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Fri, 04 Feb 2022 09:43:49 GMT

Yes my files are the default files.

I created a directory in my desktop named project c:\Users\user\Desktop\project. Then I opened the empty directory with vs code and created the application with the name project_app.

I enabled the debug options.

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Fri, 04 Feb 2022 09:38:06 GMT

We can take a look around now:

1. Have you made sure that you have taken CMakeLists and prj.conf back to how it was before you modified it?

CMakeLists:

prj.conf:

2. When you generate the build configuration, do you enable the debug option?

Also, could you tell me the path where you create the project folder?

-Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Fri, 04 Feb 2022 09:30:33 GMT

Error: c:\Users\user\Desktop\project\project_app\build\nrf52840dk_nrf52840.dts.pre.tmp:680.1-8 syntax error
FATAL ERROR: Unable to parse input tree
CMake Error at C:\Users\user\ncs\v1.8.0\zephyr\cmake\dts.cmake:225 (message):
command failed with return code: 1
Call Stack (most recent call first):
C:\Users\user\ncs\v1.8.0\zephyr\cmake\app\boilerplate.cmake:545 (include)
C:\Users\user\ncs\v1.8.0\zephyr\share\zephyr-package\cmake\ZephyrConfig.cmake:24 (include)
C:\Users\user\ncs\v1.8.0\zephyr\share\zephyr-package\cmake\ZephyrConfig.cmake:35 (include_boilerplate)
c:\Users\user\Desktop\project\project_app\build\CMakeLists.txt:4 (find_package)

-- Configuring incomplete, errors occurred!
FATAL ERROR: command exited with status 1: 'c:\Users\user\ncs\v1.8.0\toolchain\opt\bin\cmake.EXE' '-DWEST_PYTHON=c:\Users\user\ncs\v1.8.0\toolchain\opt\bin\python.exe' '-Bc:\Users\user\Desktop\project\project_app\build' '-Sc:\Users\user\Desktop\project\project_app' -GNinja -DBOARD=nrf52840dk_nrf52840 -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=On -DNCS_TOOLCHAIN_VERSION:STRING=NONE -DBOARD_ROOT:STRING=c:/Users\user/Desktop/project/project_app -DCONFIG_DEBUG_OPTIMIZATIONS:STRING=y -DCONFIG_DEBUG_THREAD_INFO:STRING=y -DDTC_OVERLAY_FILE:STRING=c:/Users/user/Desktop/project/project_app/nrf52840dk_nrf52840.overlay -DCONF_FILE:STRING=c:/Users/user/Desktop/project/project_app\/prj.conf

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Fri, 04 Feb 2022 09:26:10 GMT

Could you attach the detailed error message that you get?

-Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Fri, 04 Feb 2022 09:18:26 GMT

Hi,

I tried renaming the overlay. It seems the problem lies within the synthax of my overlay because I have the same issue.

I did add the DT_ALIAS but I did not mention it ....

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Fri, 04 Feb 2022 09:11:18 GMT

Hi Charles,

So first, you need to check whether you have named the overlay file's right. Which DK are you working with? In case you are using a nRF52840DK, you should name your overlay file "nrf52840dk_nrf52840.overlay". Exception is in the case of nrf5340, for which you name it as "nrf5340dk_nrf5340_cpuapp.overlay". Basically, you name it after the board.

Next, you don't have to modify the CMakeLists or prj.conf. The overlay files will be detected and used to modify the devicetree if you put the overlay file in the the project file. It should look something like this:

You could also place your overlay files inside the "boards" folder (that would be more clean 🙂)

Now you can see in your main.c, the line #if DT_NODE_HAS_STATUS(PWM_LED1_NODE, okay). But the compiler has not seen PWM_LED1_NODE defined before, and the same applies for PWM_LED2_NODE . So, you could try defining those too in the main.c as follows:

Also, try modifying the 'aliases' in your overlay as follows:

{
    aliases {
        pwm-led0 = &pwm_led0;
        pwm-led1 = &pwm_led1;
        pwm-led2 = &pwm_led2;
    };

Regards,

Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Thu, 03 Feb 2022 15:55:56 GMT

Hi again,

I am getting the hang a how to deal with many things in the SDK but I still can't add functionnalities as I wish.

I tried to add node using an overlay the same way I did previously but it seems it does not work.

EDIT :

To be precise, I started from the PWM_blinky exemple.

Then I added the files device_overlay.overlay and device_conf.conf (this one is empty for now).

Overlay:

/ {
    aliases {
        pwm_led0 = &pwm_led0;
        pwm_led1 = &pwm_led1;
        pwm_led2 = &pwm_led2;
    };

    &pwm0 {
        status = "okay";
        ch0-pin = <13>;
        ch0-inverted;
        ch1-pin = <14>;
        ch1-inverted;
        ch2-pin = <15>;
        ch2-inverted;
    };

    pwmleds {
        compatible = "pwm-leds";
        pwm_led0: pwm_led_0 {
            pwms = <&pwm0 13>;
            status = "okay";
        };
        pwm_led1: pwm_led_1 {
            pwms = <&pwm0 14>;
            status = "okay";
        };
        pwm_led2: pwm_led_2 {
            pwms = <&pwm0 15>;
            status = "okay";
        };
    };
};

I added the following lines in the CMaleLists.txt :

set(DTC_OVERLAY_FILE
  ${CMAKE_CURRENT_SOURCE_DIR}/device_overlay.overlay
)
set(CONF_FILE
  prj.conf
  ${CMAKE_CURRENT_LIST_DIR}/device_conf.conf
)

Then I modified the main.c by adding these lines:

#if DT_NODE_HAS_STATUS(PWM_LED1_NODE, okay)
#define PWM1_CTLR	    DT_PWMS_CTLR(PWM_LED1_NODE)
#define PWM1_CHANNEL	DT_PWMS_CHANNEL(PWM_LED1_NODE)
#define PWM1_FLAGS   	DT_PWMS_FLAGS(PWM_LED1_NODE)
#else
#error "Unsupported board: pwm-led1 devicetree alias is not defined"
#define PWM1_CTLR	    DT_INVALID_NODE
#define PWM1_CHANNEL   	0
#define PWM1_FLAGS    	0
#endif

#if DT_NODE_HAS_STATUS(PWM_LED2_NODE, okay)
#define PWM2_CTLR	        DT_PWMS_CTLR(PWM_LED2_NODE)
#define PWM2_CHANNEL	    DT_PWMS_CHANNEL(PWM_LED2_NODE)
#define PWM2_FLAGS	        DT_PWMS_FLAGS(PWM_LED2_NODE)
#else
#error "Unsupported board: pwm-led2 devicetree alias is not defined"
#define PWM2_CTLR	    DT_INVALID_NODE
#define PWM2_CHANNEL  	0
#define PWM2_FLAGS	    0
#endif

and modifying the first PWM accordingly.

When I try to bulid the application I get the error message :

synthax error*

FATAL ERROR: Unable to parse input tree

Best Regards,

Charles

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

Priyanka — Thu, 03 Feb 2022 09:30:00 GMT

Hi Charles,

As a beginner to the nRF Connect SDK, I can understand your confusion as it is quite different from your previous environment. But once you get the hang of it, it gets very convenient. I would recommend you to take a look at all the parts of our Getting Started Guide. Even though 2 specific boards are mentioned here, the working is quite similar to all the DKs.

In order to begin with the VS Code extension, we have a tutorial series on Youtube.

There is blinky and blinky_pwm sample in Zephyr as shown below:

You can try implementing all this. But Kindly go through the guides and before you begin everything just make sure you have the nRF Connect SDK installed properly. First you should install the nRF Command Line Tools, and then you could try installing the nRF Connect for Desktop.

Also, in the Guide, there is a detailed explanation of creating overlay files and working with the various pins etc so as to not make any direct modifications to the devicetree.

Regards,

Priyanka

RE: Getting Started with NCS (NRF Connect SDK) with simple PWMs.

c.tessierpiart — Thu, 03 Feb 2022 09:16:04 GMT

Hi again,

It seems I missed a the exemple related to my needs.I found the basic exemples and I can now interact properly with the board.

However, I am still confused about the right behavior in NCS. Is there a way to modify GPIO without touching the basic configuration ? It doesn't feel right to change this kind of file.

Best regards,

Charles