Today I got a 2.8" USB Touch Screen by Robopeak, which is a low cost USB display module. By taking the advantage of the USB, this product can be directly powered and be easily connected with the different kinds of Mini-PCs such as Raspberry-pi, Cubieboard(I/II/III), pcDuino, routers with USB and this like. The tutorial by Robopeak is really detailed. Thus following it, it will be conveniently to get start with.