On the right is a state diagram for our morse code reader, with all the events filled in. I have given each event a name and an action (the text after the / character). Some of the events cause the morse system to change state, others cause the system to perform an action and then remain in the same state (these are the ones with loops).

This is an actual state diagram as used in a software design tool. It allows us to refine the design of our device to give it the correct behaviour.

Note that I have added a power off state to the diagram. When the system starts up it begins in this state and then move into the QUIET state.