https://hackaday.com/2016/09/20/rc-drag-racing-christmas-tree-and-speed-trap/
RC Drag Racing Christmas Tree And Speed Trap | Hackaday
Sep 20, 2016 - In the drag racing world, a Christmas tree is the post at the start line that sequentially lights up a set of yellow lights followed shortly after by a green...
drag racing christmas treespeed traprchackaday