USB 7-Segment Numeric Display
  Manufactured by Delcom Engineering
  
  Device Information
  ------------------
  USB VENDOR_ID	0x0fc5
  USB PRODUCT_ID	0x1227
  Both the 6 character and 8 character displays have PRODUCT_ID,
  and according to Delcom Engineering no queryable information
  can be obtained from the device to tell them apart.
  
  Device Modes
  ------------
  By default, the driver assumes the display is only 6 characters
  The mode for 6 characters is:
  	MSB 0x06; LSB 0x3f
  For the 8 character display:
  	MSB 0x08; LSB 0xff
  The device can accept "text" either in raw, hex, or ascii textmode.
  raw controls each segment manually,
  hex expects a value between 0-15 per character,
  ascii expects a value between '0'-'9' and 'A'-'F'.
  The default is ascii.
  
  Device Operation
  ----------------
  1.	Turn on the device:
  	echo 1 > /sys/bus/usb/.../powered
  2.	Set the device's mode:
  	echo $mode_msb > /sys/bus/usb/.../mode_msb
  	echo $mode_lsb > /sys/bus/usb/.../mode_lsb
  3.	Set the textmode:
  	echo $textmode > /sys/bus/usb/.../textmode
  4.	set the text (for example):
  	echo "123ABC" > /sys/bus/usb/.../text (ascii)
  	echo "A1B2" > /sys/bus/usb/.../text (ascii)
  	echo -ne "\x01\x02\x03" > /sys/bus/usb/.../text (hex)
  5.	Set the decimal places.
  	The device has either 6 or 8 decimal points.
  	to set the nth decimal place calculate 10 ** n
  	and echo it in to /sys/bus/usb/.../decimals
  	To set multiple decimals points sum up each power.
  	For example, to set the 0th and 3rd decimal place
  	echo 1001 > /sys/bus/usb/.../decimals