Toggle blinking rate of LED at pin 13 using interrupt on pin 2 
volatile int blinkingRate = 5000; int 
i=0; int ledPin = 13; void setup() { 
 // put your setup code here, to run once: 
 
 pinMode(ledPin,OUTPUT); // pinMode(2, INPUT); 
attachInterrupt(digitalPinToInterrupt(2),changeBlinkingRate,RISING); 
Serial.begin(9600); 
}
void loop() { 
 // Serial.println("Hello"); digitalWrite(ledPin,HIGH); 
delay(blinkingRate); digitalWrite(ledPin,LOW); 
delay(blinkingRate); 
} 
void changeBlinkingRate(){ 
Serial.println(blinkingRate); if(blinkingRate 
== 5000){ blinkingRate = 100; 
 } 
else{ 
 blinkingRate = 5000; 
 } 
 Serial.println("---------------"); 
} 
Toggle LED using interrupts at pin 2 and pin 3 
volatile int output = LOW; int 
i=0; int ledPin = 13; void 
setup() { 
 pinMode(ledPin,OUTPUT); 
 attachInterrupt(digitalPinToInterrupt(2),buttonPressed1,RISING); 
attachInterrupt(digitalPinToInterrupt(3),buttonPressed2,RISING); 
Serial.begin(9600); 
} 
void loop() { 
 // put your main code here, to run repeatedly: 
 noInterrupts(); delay(10000); 
 ++i; 
 digitalWrite(13,output); interrupts(); 
} 
void buttonPressed1(){ output = 
LOW; 
 Serial.println("Interrupt 1"); 
} 
void buttonPressed2(){ output = 
HIGH; 
 Serial.println("Interrupt 2"); 
} 
Increment/ Decrement variable depending of interrupt from pin 2 then 3 or pin 3 then 
2 
volatile int blinkingRate = 5000; 
volatile int output = LOW; int 
I1=0,I2=0; int count = 0; int ledPin = 
13; void setup() { 
 pinMode(ledPin,OUTPUT); 
 attachInterrupt(digitalPinToInterrupt(2),buttonPressed1,RISING); 
attachInterrupt(digitalPinToInterrupt(3),buttonPressed2,RISING); 
Serial.begin(9600); 
} 
void loop() { 
 // put your main code here, to run repeatedly: 
 digitalWrite(13,output); delay(10000);
} 
void buttonPressed1(){ 
 if(I1 < I2) 
 { 
 Serial.println("I2 -> I1"); count--; 
 Serial.println(count); 
 I2 = 0; 
 } 
 I1 = 1; 
} 
void buttonPressed2(){ 
 if(I2 < I1) 
 { 
 Serial.println("I1 -> I2"); count++; 
 Serial.println(count); 
 I1 = 0; 
 } 
 I2 = 1; 
}