Binary Serial Data idle start 1 lsb 0 1 0 msb stop Robust hi start 0 0 msb lo idle 1 lsb 1 stop Concise Serial data bits for ASCII "A" (Little Endian) idle start lsb msb stop 1 0 1 0 1 0 1 -5 -1 0 1 6 7 8