Enabling eDRX on mqtt_simple on nRF9160

[Mohammad Amin]

Hi,

I want to activate eDRX on mqtt_simple example and measure the current consumption. I guess based on the code, by enabling "CONFIG_LTE_EDRX_REQ" it will be activated. Is there anything else that I should do in order to reduce power consumption?

My other question is about measuring the current, I read in the current measurement instruction on this topic but I want to know if it is possible to use power profiler kit on nRF9160 to measure the power.

[Bjørn Kvaale]

Update: Woops, forgot to answer your first question  Just add the following code to the mqtt simple example (after the modem_configure() function is a good place):

        err = lte_lc_edrx_req(true);
        if (err) {
                printk("ERROR: set edrx %d\n", err);
                return;
        }

This function should be defined in lte_lc.c. You can then easily check to see that edrx is set by using the following AT command in LTE Link Monitor: 

AT+CEDRXS?

You can naturally also check to make sure that no error has been returned.

No, you cannot use the power profiler kit to measure the nRF9160 DK current consumption. If you have the v0.8.5 nRF91 DK, just follow the User Guide found here. If you have an older version of the nRF91 DK (i.e. <v0.8.5), take a look at this devzone case.

[Mohammad Amin]

Thanks. eDRX now is working. My development kit version is older than 0.8.5. Just one question. I am confused, should I cut the SB43 or SB44 for the current measurement?

[Bjørn Kvaale]

You should cut SB44 on the DK.