Thanks to sparr
, and eil
for your inputs.
I really liked the link,http://www.beyondlogic.org/spp/parallel.htm
, sparr. Good find.
These comments have helped me draw a circle around some of the issues - here's the net as I see it so far:
1) USB is electrically practical, but the barrier appears to be the rich, packet-based, USB protocol. Maybe too rich even for the relatively verdant code space budget of a '328. Check it out here: http://www2.rad.com/networks/2000/usb/maintxt.htm
2) TTL has a simpler protocol, but the barrier appears in the number of pins required by the Centronics
parallel interface standard. More, by half, than Arduino has available.
3) Ethernet - Appealing, but the barrier is the requirement of an ethernet friendly printer who's IP address would be fixed and known to the Arduino.
Hacking is an addiction. Arduino is the gateway drug.