I'm now working on adding an LCD display to my Gumstix. Not the 4.3" Samsung display from gumstix.com, but a smaller 128x64 monochrome display from SparkFun Electronics. So why not a superfancy color display? Because the monochrome display uses only about 3.5mA @ 5V = 17.5mW (without background light). I'm connecting the display to an Atmel AtMega16, and communication between the Gumstix and the AtMega is done using a serial connection. I could have connected the display more or less directly to the Gumstix, but I would have needed some kind of level conversion (Gumstix @ 3.3V, LCD display @ 5V) for 14 IO lines, and any error in the connection might fry the Gumstix. So I decided that a serial connection would be much easier to get right, and if I fried the AtMega it would be pretty cheap to replace.
Later I'm going to add temperature sensors to measure the temperature in the different rooms in our house, and outside too.
