Mqtt & Sensor example - PSM Mode on nrf9160dk

[Hkhan7861]

Good day to all

I am at the final stages of developing a program for collecting sensor information from a UART and publishing it onto a mqtt server.  Currently the device is running at 22mA before it enters PSM mode and  at 660 uA when in power saving mode.  Ive also experimented with the standard mqtt_simple sample in PSM mode and it is around 500uA when in power saving mode.  I was hoping for a lot smaller and was wondering if it is possible to go lower.  Is there anything I can change and if so, how can i do it?  Thank you .

Kind regards,
Hassan 

[Didrik Rokhaug]

Hi,

e also experimented with the standard mqtt_simple sample in PSM mode and it is around 500uA when in power saving mode.

Do you have the UART running?

If you don't need UART for your project, you can disable it by setting CONFIG_SERIAL=n (if you have logging, etc., enabled, this might cause some Kconfig warnings. You can either disable everything else that uses the UART, or ignore them after verifying that they are not important).

Best regards,

Didrik

[Hkhan7861]

Hello

Yes, I need one UART running for my sensor.  The rest are disabled.  Either way, is one UART supposed to cause such a big current? I really don't know.

Kind regards,

Hassan

[Didrik Rokhaug]

You should be able to deaktivate the UART dynamically by setting CONFIG_PM_DEVICE=y, and then calling pm_device_action_run().

E.g.: pm_device_action_run(uart, PM_DEVICE_ACTION_SUSPEND);

[Hkhan7861]

Thank you ! this has worked and solved my problem! 

Kind regards,

Hassan