Undefine reference to "app_timer_start"

RE: Undefine reference to "app_timer_start"

AndreasF — Tue, 03 Sep 2019 05:47:17 GMT

Hi.

Please make sure that you download SDK 15.3 here.

If you have not worked much with your project, I suggest that you start a new project with a clean downloaded SDK so that you are sure that it contains the correct files.

Best regards,

Andreas

RE: Undefine reference to "app_timer_start"

lsvw1217 — Mon, 02 Sep 2019 21:13:27 GMT

Hi Andreas and awneil,

Oh I didn't know that. So I tried installing a whole new SDK 15.3 and deleting nrfx_power_clock.c and also make sure app_timer is enabled in the sdk.config. But the same error still shows up.

I've tried to search the error online and found this.

https://devzone.nordicsemi.com/f/nordic-q-a/51106/linker-issue-in-sdk15-2

According to Amanda, it might be due to different version of app_timer.c in the SDK.

But right now I'm using a whole new SDK 15.3, and files are not modified. So I think they should be from the same version.

Is there anything else I can try? Maybe download a previous version of SDK?

Also, could you provide a link to download the newest version of SDK? Maybe I'm downloading the wrong one.

Thank you so much!

RE: Undefine reference to "app_timer_start"

awneil — Mon, 02 Sep 2019 10:05:12 GMT

[quote userid="73862" url="~/f/nordic-q-a/51645/undefine-reference-to-app_timer_start/207309"]adding [anything] from previous SDK[/quote]

is never a good idea!

😮

The whole point of going to all the effort of making a separate SDK release is (as AndreasF says) that things are not the same - so you can't just go taking stuff from one SDK and dropping it willy-nilly into a different SDK!

RE: Undefine reference to "app_timer_start"

awneil — Mon, 02 Sep 2019 10:00:29 GMT

Not having the header #included in the source where needed would give compiler errors (or warnings) - but these are Linker errors.

The header gives the necessary declarations to the compiler - but the Linker needs to see the definitions.

http://c-faq.com/decl/decldef.html

This error usually means that the header has been #included in the source (giving the declarations to the Compiler) - but the .c (or pre-built binary) containing the definitions is missing - hence the Linker complains about things being "un-defined"

The above is standard 'C' stuff - not specific to Nordic or microcontrollers.

But with the Nordic SDK specifically there is an extra twist: many features have to be enabled by settings in the sdk_config.h; so, even with the correct headers #included, and all the correct .c files in the Project, you can still get 'Undefined' Linker errors - because the content of the 'C' files is disabled by conditional compilation such as:

#if NRF_MODULE_ENABLED(NRF_CLOCK)

RE: Undefine reference to "app_timer_start"

AndreasF — Mon, 02 Sep 2019 09:27:03 GMT

Hi.

[quote user="lsvw1217"]I made a modification and that is adding "nrfx_power_clock.c" from previous SDK since it wasn't included in the newest SDK.[/quote]

Can you please remove nrfx_power_clock.c from the project? This file is in SDK 15.3 split up into two different files, nrfx_clock.c and nrfx_power.c.

And add the file you need, nrfx_clock.c.

Best regards,

Andreas

RE: Undefine reference to "app_timer_start"

lsvw1217 — Mon, 02 Sep 2019 08:45:08 GMT

Hi Andreas,

I was using the newest SDK "nRF5_SDK_15.3.0_59ac345".

I made a modification and that is adding "nrfx_power_clock.c" from previous SDK since it wasn't included in the newest SDK.

I got the "nrfx_power_clock.c" from "nRF_SDK_15.2.0_9412b96" so I also try using this SDK but the same error showed up.

Please advise. Thank you!

RE: Undefine reference to "app_timer_start"

AndreasF — Mon, 02 Sep 2019 08:09:34 GMT

Hi.

Which SDK are you using? Have you done any modificatiosn?

Have not seen SWIAPP_TIMER_CONFIG_SWI_NUMBER_EGUAPP_TIMER_CONFIG_SWI_NUMBER_IRQn before.

Best regards,

Andreas

RE: Undefine reference to "app_timer_start"

lsvw1217 — Mon, 02 Sep 2019 07:00:54 GMT

Hi guys,

Thank you for the speedy reply. I've included the app_timer.h and app_timer.c.

After I enabled the app timer in sdk_config.h, I did it by change from "APP_TIMER_ENABLED 0" to "APP_TIMER_ENABLED 1". Is this the correct way to do it?

If this is the correct way, after I enable the app timer, I got another error shown in the attach picture.

Is this something to do with settings in sdk_config again?

Thank you for helping again.

RE: Undefine reference to "app_timer_start"

AndreasF — Mon, 02 Sep 2019 06:43:37 GMT

Hi.

Have you also enabled the app timer in sdk_config.h?

Best regards,

Andreas

RE: Undefine reference to "app_timer_start"

RSA — Mon, 02 Sep 2019 06:21:17 GMT

Did you include app_timer.h in main.c?you should also include the .h in user includes! for some files, you also need to include the .c file in the project directory tree (i get a similar error when my app_timer.c isn't in the file tree) If you're using the template project all this should already be set up.