Raw behavioural specs utilizing the state diagram for the coffee machine controller explained as follow.
State events
State actions
State variables
Draw diagram
The machine operates at hourly interval and display (no minutes) utilizing 24hr display. Default display is current time however it modifies to brew display when Brew button is pressed. Every time Hr button is pressed, the time advances by 1 (current or brew time according to current display).
The machine is always set to the brew; only brew time can be modified. When brewing, a red light is on, and it shuts off after 1 hour.