Lab exp#5: "Interrupts"

For Microcontroller AVR Atmega328p writing code on

(C program code + ISIS) A car park has two gates, one for entering cars and the

other for leaving cars. When a car enters the parking area, a pressure

sensor activates a switch that is connected to pin INT0 which generates

external interrupt to open the enterance gate (LED at pin PC2) for the car to enter.

When a car exits the parking area, a pressure

sensor activates a switch that is connected to pin INT1 which generates

external interrupt to open the exit gate (LED at pin PC4) for the car to leave.

Define a glabal variable 'ncars' to hold the number of cars in the

parking area. If 'ncars' reaches 10, then disable the external interrupt

INT0 to prevent more cars from entering and turn on an LED on pin PB5

to show that there is no vacancy in the parking area. When 'ncars' gets

below 50, then enable the external interrupt INT0.

The system should always display 'ncars' on the PC screen every

5 seconds. This should be done via interrupt of TC1 to produce

the 5-seconds delay.

C program code