Ethan Yu
Ethan Yu


  • computervision
  • hardware
  • software

For the Spring 2018 semester, I recruited from USC Makers and led a team of five to create the Obliterator 9000, which is a rewired automatic Nerf gun that fires whenever someone is detected in front of it. This was also my first time as a project manager, and I learned a LOT about fields that I knew little about, such as electronics and management.

Our team at showcase! Keynote speaker Allen Pan loved our project the most for being the craziest!

On the hardware side, we took apart the Nerf HyperFire, disconnected the wires connecting the switch controlled by the trigger, and soldered it to an electric relay that we controlled with a Raspberry Pi. We also added the Raspberry Pi camera to the Pi so that we can feed vision data to our Pi.

On the software side, we used OpenCV to run a body detection algorithm. If the center point of the bounding box of a person is within a certain range, then we fire a signal from our Raspberry Pi to our electric relay, closing the circuit in the gun and enabling the gun to fire. We send a HI signal for a few seconds, and after that time period, we reevaluate again to see if a person is within range and fire again.

This video is a demo of the Obliterator shooting at me when I walked in front of it!

Here is a checkpoint slide updating our progress halfway through the semester:

This covers our experiments with controlling the gun using an Arduino to send signals to the relay, using OpenCV to detect people, and powering the stepper motor.