nrf52840 FPU

[Liuguofeng]

dear all

  I use nrf52840 to compile a library with floating-point operation. I configured it in my *. Conf

CONFIG_ FPU = y, but we can't find sqrtf, sinf, logf and so on. I know you can use these functions if you include math. H in keil. But how can I use these functions in NRF connect SDK?

best regards

[Marte Myrvold]

Hi,

To enable floating point formatting you must set the following config:

CONFIG_CBPRINTF_FP_SUPPORT=y

Please add this to prj.conf and see if it fixes your issue.

Best regards,

Marte

[Liuguofeng]

Nice to meet  you Mrte

I added it as you suggested。

pri.conf 

CONFIG_FPU=y
# CONFIG_FPU_SHARING=y
CONFIG_NEWLIB_LIBC=y
# CONFIG_NEWLIB_LIBC_NANO=y
CONFIG_CBPRINTF_FP_SUPPORT=y

# Set CONFIG_NEWLIB_LIBC_FLOAT_PRINTF if printf should be able to print float
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y

But the problem remains unsolved。

Here is my compilation error section

Best regards,

Liuguofeng

[Marte Myrvold]

Hi,

Could you try setting the following as well?

CONFIG_MAIN_STACK_SIZE=2048
CONFIG_SSE=y

Which version of NCS are you using?

Best regards,

Marte