ncs1.61 peripheral_uart : enable uart when connected and disable uart when disconnected

[RHeine]

Hi,

I work with win10 laptop, Toolchain  nrf Connect SDK 1.6.1 on a nrf5340dk.

On peripheral_uart sample, I would like to enable uart when a device is connected and I want to disable uart when device is disconnected to reduce consumption.

There is the consumption mesure by PPK2:

It's seem that between two advertisings the consumption is due to the enable uart.

I need to have the lowest consumption when the nrf5340dk is advertising.

First step, I tryed to disable uart from prj.conf:

CONFIG_SERIAL=n & CONFIG_LOG=n

but after build and download the 4 led were ON and the was no more advertising.

Second step, I tryed to disable uart from the overlay file:

&uart0 {
    status = "disable";

};

but after build and download there was no led on and no more advertising.

There is my project:

5040.peripheral_uart.zip

Could you give me, please,  an example how to enable uart when a device is connected and disable uart when device is disconnected ?

Best regards,

Rob.

[Kazi Afroza Sultana]

Hello Heine,

Good Morning.

I have looked at your code and configuration file. The error you get 'undefined reference to 'pm_device_state_set'. The issues may be not related to the UART. It seems that pm_device_state_set() is only defined if CONFIG_PM is set the prj.conf. You can try this first. Set the CONFIG_PM and see if it defined then.

Best Regards,

Kazi Afroza Sultana

[RHeine]

Good morning Kazi Afroza Sultana,

Thank you for your answer. 

Just before your answer, I made progress.

I discover that the error disappears when I put "CONFIG_SERIAL=n".

Then I discover the blog : Optimizing Power on nRF5340 SoC Designs

https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/optimizing-power-on-nrf53-designs

I tryed to put into prj.conf:

"CONFIG_PM=y
CONFIG_PM_DEVICE=y"

I still have no error but there is no more advertising ...

What should I do to continu advertising ?

peripheral_uart_disable_b.zip

Best Regards,

Rob.