Low power scheduled alarm system using embedded microcontroller with USB interface

This paper discusses about the design and implementation of low power automatic scheduled alarm system whose schedule and time can be programmed using a computer via Universal Serial Bus port. Educational institutions, Factories, hospitals, etc are some places where this can be primarily used. The system uses an 8 bit PIC18f4550 microcontroller, a DS12626 Sanyo 16×2 character LCD, a DS1208 Real Time Clock (RTC) and an electrical relay to drive the ringer. The LCD displays the calendar details like day, date, time with second´s accuracy. Stress is given on low power consumption system design. Power savings compared to 7segment display is also discussed. Power consumption is lowered by using ultra low power techniques by disabling unused peripheral units and by introducing sleep mode. The power down mode of the system does not affect alarm system or the display system. This is one of the advantages. The design is initially verified using MPLAB IDE and Proteus lite simulator and then the real hardware is implemented. Complete power analysis with specific interfaces of the system is also performed.