Stop-Watch

I implemented Stop Watch system with the specifications listed below:

1- I Used ATmega32 Microcontroller with frequency 1Mhz.

2- I Configured Timer1 in ATmega32 with CTC mode to count the Stop Watch time.

3- I Used six Common Anode 7-segments.

4- I Connected the six 7-segments in the project using the multiplexed technique. I used one 7447 decoder for all 7-segments and control the enable/disable for each 7-segement using a NPN BJT transistor connect to one of the MCU pins.

5- We can connect more than one 7-segment display by using the Multiplexing method. In this method, at a time one 7-segment display is driven by the Microcontroller and the rest are OFF. It keeps switching the displays using transistors. Due to the persistence of vision, it appears as a normal display.

6- I Connected 7447 decoder 4-pins to the first 4-pins in PORTC

7- I Used the first 6-pins in PORTA as the enable/disable pins for the six 7-segments.

8- I Configured External Interrupt INT0 with falling edge. I Connected a push button with the internal pull-up resistor. If a falling edge detected the Stop Watch time should be reset.

9- I Configured External Interrupt INT1 with raising edge. I Connected a push button with the external pull-down resistor. If a raising edge detected the Stop Watch time should be paused.

10- I Configured External Interrupt INT2 with falling edge. I Connected a push button with the internal pull-up resistor. If a falling edge detected the Stop Watch time should be resumed.