Hi, I have to design a digital system using both combination and sequential logic and i was wondering if someone can give me ideas/guidance as what to design.
Why don't you try to make an electronic Lock as a combinational circuit? You could use a relay that drives something only when the correct combination is done. You would need a dip switch or several switches, the relay and something to drive and gates.
You could use an extra switch hidden to change the password.
I don't have schematics on that but Im sure you can work it out.