====== Power On/Off switch ======
You can control power supplying to **ODROID-C2** while DC adaptor is connected with external switch, Sliding or Toggle Switch for example, if you connect such switch to **J4** on the board. **J4** is connected to **NCP372** (Protection IC). There is an ENABLE pin on the NCP372 and it is a low-active and have an internal pull-down resistor for default on.

|| Switch status | Output of NCP372 ||
|| ON(short) | OFF||
|| OFF(open) | ON (+5V)||

<WRAP left round alert 70%>
With this hacking, we strongly recommend to shutdown the O/S completely before turn-off. Otherwise the file system could be corrupted very easily. In Linux, for example, please make sure to execute **shutdown -r now** or **poweroff**.\\
</WRAP>

====== Alternative power input ======
The J8 pins are added for an alternative power input (for easier wiring/soldering to power supply cable on PCB rev0.2 20160226)

{{:en:c1:c2_j8_power_cable_connection.png}}


====== Alternative heartbeat LED ======
If you want to remap the blue heartbeat LED to other GPIO, refer this great instruction.

[[http://forum.odroid.com/viewtopic.php?f=135&t=22525#p151227|paulcrawford's guide on the forum]]
====== IR Remote Controller (Android) ======
----
{{:en:c1_ircon.png?direct&100 |}}
**Manufacturer Code**: 0x4DB2
^Button ^ IR code ^ Scancode ^ Android ^
|Power|0xDC|116|KEYCODE_POWER|
|Mute|0x88|113|KEYCODE_VOLUME_MUTE|
|Home|0x82|102|KEYCODE_HOME|
|OK|0xCE|97|KEYCODE_DPAD_CENTER|
|Up|0xCA|103|KEYCODE_DPAD_UP|
|Left|0x99|105|KEYCODE_DPAD_LEFT|
|Right|0xC1|106|KEYCODE_DPAD_RIGHT|
|Down|0xD2|108|KEYCODE_DPAD_DOWN|
|Menu|0xC5|139|KEYCODE_MENU|
|Back|0x9A|158|KEYCODE_BACK|
|Volume Down|0x81|109|KEYCODE_VOLUME_DOWN|
|Volume Up|0x80|104|KEYCODE_VOLUME_UP|

The IR remote key map is defined in /system/etc/remote.conf file.\\
Default IR protocol is NEC type.

====== USB Hub IC reset script ======
If you need to do power-cycle to the USB devices on the USB host ports, run below commands.\\
It will reset all the USB devices connected to the USB host ports. 
<code>
echo 126 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio126/direction
sleep 1
echo 0 > /sys/class/gpio/gpio126/value
sleep 1
echo 1 > /sys/class/gpio/gpio126/value
echo 126 > /sys/class/gpio/unexport
sleep 1
</code>

====== USB Hub IC issue ======
Every power cycle, the USB hub controller is disconnecting the USB devices at among 5~7 second after starting the boot process. \\
If you use a fast booting OS like Buildroot, Yocto and Ubuntu-Minimal, your USB devices will not work correctly. \\
To avoid this issue, you need to run your USB application software slightly later after complete the booting process. \\

Here is an example of the serious problem. Unfortunately, we couldn't find any workaround yet.\\
[[http://forum.odroid.com/viewtopic.php?f=141&t=23733|Forum Thread]]