Hello Bartosz,

Saving pins in on a large scale. Not all 15 railroad crossing is on at any given time. As the train makes it route each crossing will become active.

Each railroad crossing is different in the timing of the LED's. This is not a one man project and to encourage others to get involved the simplest circuit was chosen. It turns out to be the most flexible in adding bells and whistles.

The 80C51 needs it timers for a real time clock and baud rate generator. That doesn't leave any way of doing pulse width modulation.

Having a computer control the train adds realism to the project. Other can plan routes that add excitement. Without this the project would be come stale and others will drift away.

Regards,

Charles Bannister