Task: Enable INT0 interrupt and pin change interrupt PCINT0 to light up one LED for each in their respective interrupt service routines.
Without using STK600, connect two LED circuits as shown in Figure 1; one at PA0 and another at PA1, and two switch circuits, one at PD0 and another at PB0.
While running the example code when switch SW0 is pressed, due to pull-up the interrupt INT0 will be triggered when SW0 is released and LED0 blinks once. When switch SW1 is pressed the interrupt PCINT0 is triggered and LED1 blinks once, and when SW1 is released the interrupt PCINT0 is triggered once again and LED1 blinks once again. So a single switch action (press and release) on SW1 produces two blinks on LED1.