Alex ATmega16
do you have mini systemboard atmega16 ? ye i have one. but until this march. i dont know how program it. otherwise perhaps you have simple program? such as how to driving seven segmen? I try to design with 2x10 data connector header male - female. so its look likes shield on arduino uno. acording to board size 5x7cm not far from that size. start using Universal PCB from PCBway. i found that 3x7cm board meet my requirment.