I have to make a program to measure the distance with my ultrasonic sensor with interrupt, without using libraries. Can someone give me a hand?
That is certainly a curious requirement. Who is making you do this? What is the interrupt supposed to accomplish? What have you designed or programmed to try to make this work?
What Arduino are you using? What ultrasonic sensor are your using? What power are you using for the project? Do you have a block diagram of how you are connecting all this together?
Paul