improve marker detection by introducing timer
improve marker detection by introducing timer

bencart/track-o-bot,bencart/track-o-bot,elzoido/track-o-bot,BOSSoNe0013/track-o-bot,bencart/track-o-bot,BOSSoNe0013/track-o-bot,stevschmid/track-o-bot,elzoido/track-o-bot,stevschmid/track-o-bot,elzoido/track-o-bot