The logic required the ability ... match the chosen item's cost, the machine did not dispense. Finally, the machine needed work with only 2 d flip-flop storage bits. These were used as a state machine ...

And the machine can make only two kinds of coffee ... This curcit don't have authorizing logic. So suggest that 'manage' button is locked physically. So you need a physical key for unlocking.

You might think that a microcontroller would be needed to handle a vending machine’s logic. For one thing ... After all, the whole circuit can be thought of as a few motors, a power source ...

Counters are a sequential logic circuit used to count clock pulses arriving at ... This type of finite state machine is used in vending machines, elevators, and such like.