Ultimately the E1 will be controlled by a beagle board computer. To accomplish this I bought a Torobot 24-servo controller board, but had a really hard time getting an easy-to-use API to interface it. I tried pyUSB to no avail.
Finally I found that the Torobot USB board could be communicated with through an Arduino serial driver. Conveniently this is available through opkg:
opkg install kernel-module-cdc-acm
When the board is plugged in, it comes up as
From here you can simply echo commands to the device.
echo "#8P1500T100" > /dev/ttyACM0
This basically says “set servo 8 to position 1500 with speed 100″. Doesn’t get much simpler than that!