Stop Watch System

Overview

This repository contains the code and documentation for a Stop Watch system implemented using the ATmega32 microcontroller. The project utilizes Timer1 in CTC (Clear Timer on Compare Match) mode and a multiplexed six 7-segment display to count and display elapsed time in hours, minutes, and seconds.

Features

• Multiplexed Display: Efficiently displays time on six 7-segment displays using a multiplexing technique.
• External Interrupts:
  • Reset: Clears the timer and resets the stopwatch.
  • Pause: Stops the timer.
  • Resume: Restarts the timer from the paused state.
• Timer1 in CTC Mode: Provides precise timing functionality for the stopwatch.

---

System Design

Hardware Requirements

1. ATmega32 Microcontroller
2. Six 7-Segment Displays
3. Three Push Buttons:
   • Reset (connected to INT0)
   • Pause (connected to INT1)
   • Resume (connected to INT2)
4. Resistors and Connecting Wires
5. Power Supply (5V)

Software

The system is programmed in C using AVR libraries, leveraging interrupts and timer functionalities for accurate timekeeping.

---

File Descriptions

StopWatch.c

• Contains the main program logic and interrupt service routines.
• Implements:
  • Timer1 initialization in CTC mode.
  • Interrupt Service Routines for Reset (INT0), Pause (INT1), and Resume (INT2).
  • Multiplexing logic for 7-segment displays.

Key Functions

• Timer1_Init_CTC_Mode(): Configures Timer1 in CTC mode with a compare value of 1024.
• Interrupt Service Routines (ISRs):
  • TIMER1_COMPA_vect: Increments the time ticks.
  • INT0_vect: Resets the stopwatch.
  • INT1_vect: Pauses the stopwatch.
  • INT2_vect: Resumes the stopwatch.

---

How to Use

Setup

1. Connect the hardware components as specified in the system design.
2. Compile and upload the StopWatch.c code to the ATmega32 microcontroller using an appropriate programmer (e.g., USBasp).

Operation

• Press the Reset button to start from 0:00:00.
• Press the Pause button to stop the timer.
• Press the Resume button to continue counting.

---

Additional Information

Timer Configuration

The stopwatch is based on Timer1, operating in CTC mode with a compare value (COMP) of 1024. The timer tick duration is adjusted for accuracy by configuring the prescaler and compare value.

Display Multiplexing

The 7-segment displays are driven using a multiplexing technique to reduce hardware requirements. Only one segment is active at any given time, with rapid switching to create the illusion of simultaneous display.

---

Future Enhancements

• Add support for lap timing.
• Integrate an external display for larger viewing.
• Include EEPROM storage for saving elapsed time.

---

Author

Basel Dawoud
Contact: baseldawoud2003@gmail.com