Water cannon with app

The oldest and still most popular demo project of our customers is the water cannon from 2012: an adjustable water nozzle that can be controlled by a joystick in the center console of an old VW Passat (1990).

The water nozzle is hidden behind the VW emblem. When activated by the joystick, the emblem flips out in a flash and is ready for action.

The direction of the water jet can be controlled with a joystick in the car's center console or via an iPhone app. When controlled by smartphone, the cannon aligns according to the tilt of the accelerometer.

The spacious engine bay houses the technology. Electronics, pump and water tank are located here.

The high-pressure pump draws from a 10-liter canister and pushes the water through the nozzle at 6 bar. The range of the water jet is 12 meters.

Servo motors from the model hobby sector serve as actuators for the X and Y axes.

The electronics consist of a Wi‑Fi router, an Arduino board with Ethernet shield and the microcontroller ATMEL AVR ATMEGA 8.

For low-level hardware programming C++ was used and a JSON scripting language for the app. Data exchange between iPhone and electronics takes place via UDP packets in OSC format.

All mechanical parts were manufactured with the CNC milling machine.

Compared to a conventional VW emblem, the repurposed one shines in a striking red. The water jet glows at night in a bright blue LED light and is reminiscent of a lightsaber.

The water cannon combines classic mechanical engineering with modern information technology and shows with a wink how useful engineering can be.