Hello All,

Anyone have any ideas for an easy circuit to detect a train by 2 photodetectors (either side of the road being crossed) and make 2 pairs of 1.5-3V LEDs flash at 1 second interval.

I know there's Arduino builds and other pre-made circuits to make the flashers, but I'm hoping to produce ten of them and not spend $50 per crossing.

Any help greatly appreciated.