I have a Colibri T30 with Nvidia provided L4T rootfs. This T30 is powered by a rechargeable battery that is charged with solar panels. In order to save battery I put the T30 sleep at night with
echo +3600 > /sys/class/rtc/rtc1/wakealarm and
echo -n mem > /sys/power/state commands. The saved energy is considerable, but I wonder if it is possible to put something else to sleep apart from
echo -n mem > /sys/power/state . Iris board, reduce cpu frec… would be useful.