PIC Microcontroller Projects in C, 2nd Edition

Project 7.6—Real-Time Clock Using an RTC Chip

In this project, we will design a clock using a real-time clock (RTC) chip. We will be using three push-button switches to set the clock initially: Mode, Up, and Down. Mode button will select the date and time field, Up and Down buttons will increment and decrement the selected field, respectively.

There are several RTC chips available. The one that we will be using in this project is the PCF8583 eight-pin DIL chip. The specifications of this chip are as follows:

• Clock, alarm, and timer functions;

• I²C bus interface;

• A +2.5- to +6-V operation;

• A 32.768-kHz time base (requires an external 32.768-kHz crystal);

• Programmable alarm, timer, and interrupt functions;

• A 240 × 8 random access memory (RAM). ...