I am developing an application based on the KNOT, using GNSS and NB-IOT data transmission.
It is supposed to stay idle for a period, then send a very small amount of data to a server and revert to "idle".
The BG77 chip contains features for saving power, for instance flight mode and Power Saving Mode vs the WWAN.
But what about the KNOT itself?
Measured the current draw to approx 85mA at 24V, i.e. around 2W, this is without Wifi and BT in use.
Setting the BG77 in flight mode did almost nothing to the power draw. Same with lowering the clock frequency to minimum 550 MHz.
In many ways the Knot seems ideal to this kind of operation, but a continius draw of 2W makes it unsuitable for simultaneous battery powering and portability..
Making use of /system scheduler for performing tasks needs the RB to be up and running all the time.
Another approach would be a separate circiut based on a 555 timer and a micro relay that boots up the KNOT every x minutes, long enough to do its data acquistion and reporting, and then powering it off.
I would rather see a routerboard like the KNOT using very little power, with limited CPU performance and some kind of real "sleep mode", but I guess this does not exist....
Any of you guys that have addressed this problem?