NRF9160 Reduce power consumption

[jermi]

Hi  Nordic：

        

I use the LWM2M of NCS and found that the power consumption increases every 2.5 seconds. I use the monitor to find that the serial port is sending data. How to turn off the LOG output, and how to turn off the UART to reduce power consumption.

thanks！！

JERMI.JIN

2022.01.06

[Øyvind]

Hello, 

You can configure CONF_SERIAL and CONFIG_LOG both to n in your prj.conf. You can use the nRF9160: UDP sample as an example, as this is designed for low power.

found that the power consumption increases every 2.5 seconds.

How did you find this increase? Have you measured? Is you device using PSM?  Have a look at this guide on how to do current measurements on the nRF9160

Kind regards,
Øyvind

[jermi]

I modified it to TCPIP on NRF9160 (NCS1.8.0) UDP DEMO, and used edrx in NB mode,
CONFIG_LTE_NETWORK_MODE_NBIOT=y
CONFIG_UDP_EDRX_ENABLE=y
CONFIG_LTE_EDRX_REQ_VALUE_NBIOT="0010"

Test power consumption, the minimum is 35uA, but there will be a large current every few seconds, what else is wrong with the setting，What does the value of CONFIG_LTE_EDRX_REQ_VALUE_NBIOT specifically mean?

[Øyvind]

jermi said:

What does the value of CONFIG_LTE_EDRX_REQ_VALUE_NBIOT specifically mean?

From the KConfig reference documentation of CONFIG_LTE_EDRX_REQ_VALUE_NBIOT

Sets the eDRX value to request when NB-IoT is used. The format is half a byte in a four-bit format. The eDRX value refers to bit 4 to 1 of octet 3 of the Extended DRX parameters information element. See 3GPP TS 24.008, subclause 10.5.5.32. The value 1001 corresponds to 163.84 seconds.

From 3GPP TS 24.008 table 10.5.5.32:

More information can be found in our AT commands documentation for eDRX setting (+CEDRXS)

[jermi]

Hi：

NCS1.8.0 version lwm2m project, I added CONFIG_SERIAL=n to PRJ.CONF, but after generating the project, there is still a macro of #define CONFIG_SERIAL 1 in AUTOCONF.H, how can I cancel this macro?

JERMI.JIN