Stopwatch Project

The project consist of a display that contain a 6-digit common anode 7-segment. The seven segments are being interfaced using a 7447 decoder. Atmega32 MCU (with 1Mhz clock ) is used to maintain the clock and the interrupts.

Circuit Digram

Main functionalities

• Multiplexed 6-digit 7-segemnt that display the seconds, minutes and hoours.
• Pasue de-bounced button using an external interrupt.
• resume de-bounced button using an external interrupt.
• Reset de-bounced button using an external interrupt.
• 7447 Binary to decimal decoder.
• High persicion second calculation using compare mode using timer 1. w

Project Modulation and Structure

The project has 3 Modules.

1. clock Module:

   • Time struct.
   • init_time() to initialize a structure of type time to zero.
   • advance_second() to increment a time structure by 1 second.
   • advance_minute() Helper function for advance_second().
   • advance_hour() Helper function for advance_second().
   • display_clock() to display the clock digits from right to left .
   • get_digit() helper function for display_clock() function.
   • all function should return a SUCCESS code or and ERROR code.
   • static function maintain the usability of some functions.

2. Intterupts module:

   • cotain the configuration functions for all 3 extrnal interrupts.
   • contain all 3 ISRs for the 3 external interrupts.

3. Timer module:

   • contain the configuration function for timer 1 on ctc mode.
   • Timer_resume() to resume the timer counting.
   • Timer_pasue() to pause the timer counting.
   • Timer_reset() to reset the timer counting to 0.