Hi, =20 I just wanted to point out, being a train driver, that if this thing has th= e purpose (among others) to avoid that people stand on the railways while a= train is coming it better be 99,999% safe.=20 You have to consider that when people will realize/understand that "bright = light" equals "coming train" they will also consider that "no lights" equal= s "no train", hence a failure on the system could be fatal. In a straight tunnel it could also be easier to detect people/animals and T= HEN brighten the lights or signal the danger to the driver. =20 Just a few thoughts. =20 =20 Rossano =20 --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .