Multi-event Alarm Clock

A regular alarm clock, whether stuffed with electronics or of the mechanical variety, will not get you very far if you need to be reminded of several events during the day (for example, taking your medication). What you need is a multi-talent like the circuit described here. The circuit diagram of the Multi-event Alarm Clock shown in Figure 1 is easy to understand, the central parts being a contemporary combination of a microcontroller, a real-time clock and an LC display. At the heart of the circuit sits a powerful yet inexpensive and widely available 8051-compatible 8-bit microcontroller type AT89C2051 from Atmel. Its main features may be summarized as follows:– full 8051 software compatibility;– 2 kbytes of Flash memory;– integrated analogue comparator;– multiple outputs with LED drive capability;– static architecture (0-24 MHz)– extended supply voltage range (2.7-6 V).