Project 7.7—Real-Time Alarm Clock
This project is an extension to Project 7.5. In this project, we set up a daily alarm using the PCF8583 RTC chip. The time of the alarm can be set as in the previous project. An LED is used to indicate the alarm condition (we could have also used a buzzer) and the LED turns ON when alarm occurs. The alarm condition stays until a button is pressed to stop the alarm. The alarm occurs daily at the same time every day.
Figure 7.66 shows the block diagram of the project. The functions of the buttons are as follows:
MODE: Used to enter the clock setup mode. Keep this button pressed while resetting the microcontroller. This button is also used to move between the fields while setting the clock or the alarm time.
UP: Used ...