Clock using RTC DS12C887 & 8051 microcontroller (AT89C51) with alarm set function
DS12C887 is a real time clock (RTC) IC from Dallas Semiconductors. The RTCs provide precise time and date information. This article explains the making of a digital clock with alarm setting functionalities. RTC has been interfaced with AT89C51 to perform desired operations. This project is an improvement over Digital clock using RTC DS12C887 and 8051 microcontroller (AT89C51) with time set and has the alarm setting function also. The alarm setting function allows user to set the alarm. The clock time is displayed on the LCD. The free source code for the program is available in C.
The circuit for interfacing the RTC and 16x2 LCD with the microcontroller 8051 is shown in the circuit diagram. Port P2 is set as data port for LCD to send the data on the LCD while port P0 is set as data port for the RTC DS12C887. This is used to extract the time, date and other information from the RTC. The pins of port P1 and P3 of the controller AT89C51 are used to provide the input signals for setting the time, alarm etc. They also provide control signals for the RTC and the LCD.
LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments...
RTC DS 12C887 is widely used to provide exact time and date in many applications such as x86 IBM PC. This RTC provides time components hour, minute and second in addition to the date/calendar components of year, month and day. This chip uses an internal lithium battery, which keeps the time and da...