As a senior in high school with some knowledge on electronics and mcus, I couldn’t pass my last year without building the ultimate senior prank. The prank involved hiding a remotely operated water gun, built from scratch, behind a door and spraying students as they walked down the hall.

While I sat in the hall and “read” my math book, I had one of my hands behind my back with a finger on the trigger. From the sidelines, my hidden camera and I watched some very funny reactions to my devious school prank. Watch the video above which shows the build, the setup, and lastly the prank.

This project includes two modules: a receiver and a transmitter, both of which are driven by an ATmega8. The transmitter module is controlled using a 4-position key switch and an LED pushbutton. The key-switch turns the transmitter module on and also selects the power level for the water gun. The pushbutton is the trigger that activates the water gun. When the pushbutton is pressed, the position of the key-switch is read and a data packet is transmitted to the receiver module using the standard UART protocol. The receiver translates the data and turns on an electric fuel pump to the corresponding level of power. Varying the level of power was achieved using PWM. The electric fuel pump then pumps water out of a reservoir and through a hose. Together the transmitter and receiver modules make a remote control water gun.

This project was featured on Hackaday.

Downloads

Receiver Source Files – RX.zip

Transmitter Source Files- TX.zip

The Receiver

The Transmitter