(...) If the rcx is on the train why not mount touch sensors on the underside looking down. You could then attach small ramps to the track which would trigger the sensor. If you put the sensors on a spring loaded mounting you shouldn't have problems (...) (19 years ago, 28-Nov-05, to lugnet.robotics.rcx.nqc, FTX)
(...) That was basically my plan if I couldn't get the light sensors to work reliably. Based on Brian's post I might go back to my original design, though. (19 years ago, 28-Nov-05, to lugnet.robotics.rcx.nqc, FTX)