Please note: From a software point of view ODROID C1, C1+ and C0 are (nearly) identical. For Hardware differences between C1 and C1+ and to see how to use USB OTG on the latter please see here. C0 is a stripped down and more power efficient C1+ that can be battery powered (see here how to read out battery voltage)
Comprehensive device information and various tips&tricks can be found in Hardkernel’s wiki. Please be aware that some of the information does not apply to Armbian (eg. we use a different partition table). Schematics can be found here.
Idle consumption of an ODROID-C1+ with Armbian defaults varies between 1800 mW (@504 MHz) and 1900 mW (@1728 MHz – temperature also differs just by 2°C – for reasons please refer to the ‘race to idle’ concept.
By defining setenv hdmioutput "0" and setenv vpu "0" in /boot/boot.ini followed by a reboot you get true headless mode (no consumption savings but MemTotal increases from 804 MB to 941 MB – check /proc/meminfo if in doubt)
You can save at least 170mW by cutting power to the internal USB hub (and also all USB devices connected to any of the type A receptacles) using /sys/class/gpio/gpio4 (see description here). The same way you have full control over power consumption of a connected host powered USB disk: umount /mnt/usb && echo 0 >/sys/class/gpio/gpio4/value and echo 1 >/sys/class/gpio/gpio4/value && sleep 2 && mount /mnt/usb
Ethernet performance is ~940 Mbits/sec in TX direction and 400-500 Mbits/sec in RX direction. You might be able to tweak the latter a little, just have a look in the link one paragraph above.
the red led is a power led while the blue led is custom. Boot stage: as soon as u-boot is loaded the blue led lights solid and when kernel starts this changes to heartbeat blinking with default settings. Check cat /sys/class/leds/*blue*/trigger for other functionality.