NRF_LOG print double precision float number

RE: NRF_LOG print double precision float number

Takeshi Goda — Sat, 19 Dec 2020 18:43:39 GMT

hi,jorgen

I also encountered this problem. I struggled for a day and was puzzled.

I tried all the methods in the world.

your last hint makes me feel you are Linus.

RE: NRF_LOG print double precision float number

rolandash — Thu, 10 Dec 2020 16:32:09 GMT

Although it sounds like making no sense to me, your last hint just made my day :-)

RE: NRF_LOG print double precision float number

Jørgen Holmefjord — Wed, 09 Dec 2020 16:37:57 GMT

I do not see any ways that the logger backend could be causing this. However, one thing you should try is to use NRF_LOG_PUSH() to push the string to the internal string buffer if this is part of a larger application, and you are using deferred logging. The string may be overwritten on the stack before it is processed by the logger backends. It could look like this is the problem in your latest log message, since the length seems to be correct at 11.

RE: NRF_LOG print double precision float number

rolandash — Wed, 09 Dec 2020 16:17:11 GMT

thanks you Jørgen

I forgot to mention I am using RTT as backend of NRF_LOG

Does that matter?

RE: NRF_LOG print double precision float number

Jørgen Holmefjord — Wed, 09 Dec 2020 15:32:48 GMT

This is the project I initially used for testing with SDK 15.3.0: devzone.nordicsemi.com/.../8360.double_5F00_float_5F00_test.zip. There is also included a hex-file in the _build directory in case you want to test that.

I'm not sure if the compiler version or OS makes any difference, I'm just asking in order to try to recreate your environment as close as possible. Just tested with SDK 17.0.2 and 9 2019-q4-major, but this still works fine on my setup.

RE: NRF_LOG print double precision float number

rolandash — Wed, 09 Dec 2020 14:47:31 GMT

Hi,

I upgraded from previous version of SDK, and I am on MacOS, I think I am using following version:

GNU Tools for Arm Embedded Processors 7-2017-q4-major

gcc version 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204]

Will that make a difference?

Can you please upload your test project so I can make a comparison locally?

thank you!

RE: NRF_LOG print double precision float number

Jørgen Holmefjord — Wed, 09 Dec 2020 14:02:14 GMT

Are you using a different armgcc version than the default supported in SDK 15.3.0 (7 2018-q2-update)? Which OS are you building on?

I tested again with an unmodified example, and adding these two additional flags (-lrdimon -u _printf_float) makes the output look like I posted above in this example as well.

RE: NRF_LOG print double precision float number

rolandash — Tue, 08 Dec 2020 15:11:11 GMT

Thanks Jørgen

I tried your solution but I still get the same:

[00:00:11.836,486] <info> app: [KF] updated K gain: ?8, 11

Perhaps some other flags I also missing?

RE: NRF_LOG print double precision float number

Jørgen Holmefjord — Mon, 07 Dec 2020 13:11:01 GMT

Hi,

The Makefiles in the SDK does not include float support for printf in armgcc by default. Please try adding the flags from this post to the LIB_FILES, that seems to print the way you want in my test:

# Add standard libraries at the very end of the linker input, after all objects
# that may need symbols provided by these libraries.
LIB_FILES += -lc -lnosys -lm -lrdimon -u _printf_float

<info> app: [KF] updated K gain: 3.00088E+03, 11

Best regards,
Jørgen