Microcomputer timer

A timer unit for use with an exterior coin-operated device and designed to primarily function to turn on and off other exterior devices such as car washers, air dispensing machines, pay showers, suntan salons, vacuum equipment and the like, comprising:

• a. a case having positioned therein a single chip microcomputer comprising a plurality of circuit boards, the case having positioned inside thereof for access to the outside thereof at least two programming buttons, the case also having positioned therein a visual display for viewing from the exterior of the case, the programming buttons and the visual display being electrically connected to the microcomputer;
• b. the microcomputer containing a large scale integrated (LSI) circuit comprising at least a central processing unit (CPU), a read only memory (ROM) for program storage, and a random access memory (RAM) for general data usage;
• c. the LSI circuit functioning to perform the following functions upon activation:
• (1) display a friendly message to the user of the timer on the visual display,
• (2) display a diagnostic message on the visual display when an error is recognized by the computer;
• and
• (3) flash the visual display at a predetermined time near the end of the timed cycle;
• d. the two programming buttons being designed to signal to the microcomputer to perform the following functions:
• (1) examine and/or clear the coin inventory,
• (2) change the time given by the timer unit for each coin deposited in the coin-operated device,
• (3) change the number of coins required to start the timed cycle,
• (4) modify coin security parameter in the microcomputer;
• e. the microcomputer functioning to compute an error in the timer unit and to display a code for one or more of the following diagnostic messages relating to the error which is then displayed on the visual display:
• (1) stuck coin
• (2) computer memory loss
• (3) slug;
• f. the microcomputer also functioning to perform the following:
• (1) indicate on the visual display a time set on the timer unit;
• (2) wait a predetermined time to see if more coins have been deposited in the coin-operated device before indicating on the visual display, time on the timer unit;
• (3) indicate, on the visual display, time remaining on the timer unit,
• (4) turn on and off the other exterior devices at a predetermined time;
• and
• g. the microcomputer having a nonvolatile memory in case of a power interruption to the computer power source, the nonvolatile memory permitting the computer to keep track of coin inventory in the coin-operated device by counting each coin as the coin is deposited in the coinoperated device by the user of the timer:
• (1) the coin inventory being capable of being examined on the visual display from outside of the timer unit by signaling to the microcomputer by waving a strong magnet over the visual display.