Help with interview questions [ASAP]

[stm32f4]

Help with an interview question [ASAP]

Any help in solving the following question is much appreciated. Thanks in advance.


We have 1 bridge with 2 traffic lights at both ends.
The two traffic flows need to alternate in accessing the bridge.
a) Design a state machine to control the traffic lights.
b) How do you minimize the implementation logic?

 

[chuckey]

a, figure out the relative timing and colours of the lights (hint, red, red and amber, green, amber red X2). Use a hard ware watchdog timer to switch all lights to red if micro/power switches fails. Make sure that on restoration of power all lights start on red.
b, this is trivial use a PIC, the real cost is in the civil engineering and the power switches.
Frank