This is a special USB Host adapter that fits and allows to connect any standard USB A device (or an external Mini Hub) to the Neo Freerunner.
It does not have the electronic signalling of a real USB OTG plug to automatically switch between client and host mode but the commands are shown below.
Note: since this is not a fully standard compliant device it is possible to do something harmful (i.e. two devices in being connected in Host Mode and trying to provide each other with power). Therefore, be careful and use at your own risk.
echo "host" > /sys/devices/platform/s3c2410-ohci/usb_fmode
echo "1" > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo "device" > /sys/devices/platform/s3c2410-ohci/usb_fmode
echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode