Wrist Watch Example

Product description

The "TMX Digital Mystery Answer" watch has all the features that users expect in a digital watch, and some unusual features.

The watch has the following features:

• Time and date displayed on the screen. Current time is in large numbers, date is in small numbers above it.
• Light: Pressing the light button on the side of the watch activates a light while the button is pressed. Pressing and holding that button for 3 seconds turns on the light and keeps it on, until the button is held again for 3 seconds or up to 2 hours. After 2 hours, it will automatically turn off.
• Alarm. A daily alarm may be set for a given time. The alarm may be enabled or disabled. When the alarm is enabled and the alarm time is reached, the watch will beep fast for 5 seconds, then slowly for 30 seconds, then fast for another 5 seconds. Pressing any button stops the alarm sound (in addition to performing its normal function).
• Timer. Timer mode shows a count-up timer that starts at 00:00. When the timer is started, it counts up. Pressing the start/stop button will pause the timer, pressing it again continues counting up. Pressing and holding the button for 3 seconds resets the timer to 00:00 and stops counting.
• Mystery answer. After entering this mode, the screen initially displays "ask now". The user may ask a yes-or-no question aloud and press the start/stop button, this will display a randomly selected answer that is one of the following: "yeah", "yeah right", "no", "no doubt", "keep trying", "keep dreaming". Whenever the display has more than one word, only one word is displayed for 2 seconds, then the other word is displayed for 2 seconds, alternately. The answer is displayed until the user leaves this mode, or he/she presses start/stop again for a new answer. Note: these strings are for the English version of the watch, we will need to use completely different strings in other countries without reprogramming the logic of the watch.

The user may cycle among all modes (date/time, timer, mystery answer) by pressing the mode button.

Features may be used in combination. E.g., a user may use the light to see the timer. E.g., the alarm might go off while reading a mystery answer. E.g., the timer may be running while the user checks the date/time or a mystery answer. Other combinations are possible.

For the purpose of this problem, we will assume that the date, time, and alarm time are already set and we will not design any modes to adjust them.