What I made: It is simply a servo activated crossbow. IT is made of a motor, some wood, Arduino, rubber bands, and a PIR sensor. It uses a servo to set it off. It shoots cylindrical objects.
How I made it: I build this using pieces of wood found around the house and electronic parts I already had. I used hot glue and screws to hold it together. I worked by myself. I first thought of doing it out of Lego Technic parts, but thought that wood would be stronger.
Where I made this: I made this at my house spending some of my time in my room.
What I learned: I learned that Arduino can be good for many things, I also learned about passive sensors, and how simple parts can be powerful.