I made a robot with my friend who can deliver gifts if he sees a house. He perceives them with the ultrasonic sensor. I program a program, but it isn´t so good, because the ultrasonic sensor perceives more than I want (example an invisible object in the air). Therefore I steer the robot over Bluetooth in the video. In my program he runs when it gets dark, that the little kids can´t see him. If it gets clear, he drive away. I had many problems with the ´gift gun´. I had made three constructions of it, before I had this ´gun´.