Using an arduino to deal with thieves.


My teammate and I worked to create an Arduino device that can be hooked onto a person's belongings and armed to protect them from theft. Originally the device used only an alarm and blinking LED, but we were pushed towards making something more playful and attention grabbing, so we added a silly string shooter. The entire device can be armed and disarmed by the owner’s remote control. If anyone tries to steal anything while the system is armed, they are sprayed with silly string, potentially scaring them and making it clear to any bystanders who the perpetrator is.

Learning how to build and code Arduino devices was a difficult, but exciting challenge. The majority of our time during the quarter was spent debugging and testing Arduino components. In the end we were able to create a device that utilized the Arduino in a useful and playful manner.



Completed: Spring 2013

Duration: 10 weeks

Course: Tangible Interactions

Professor: Dominic Muren

Collaborators: Gavia Angell

Role: Concept, Arduino Device, Programming, Construction, Troubleshooting

Device diagram

Device in action


The challenge was to create an Arduino based device that can protect a person’s possessions while they’re away, and do so without any previous Arduino experience. From a programming perspective, this project posed some challenges because of the binary nature of the Arduino device, but we were able to get all of the components to arm and disarm with the user’s remote control regardlessly.

The most difficult part of the project, which required thirty straight hours of work on the final two days to get functioning, was the servo pulley system used generate the force needed to press down on the silly string can.


Testing the Arduino

Testing the Arduino

Inside of our device

Inside of our device

Hidden silly string can

Hidden silly string can

Testing the silly string can

Testing the silly string can


This project was all about iteration. Each week, my partner and I got a couple more things working. As soon as all of the components were functioning properly with the code, we constructed their container, attached a battery, and set up a pulley system for the silly string can. The container was designed to keep the LEDs visible and enable the infrared remote to still work while keeping the silly string can hidden inside. We created the container from frosted plastic and wood, shaping it as an ambiguous cube to keep its identity and function hidden from thieves.

Thanks to code from other Arduino projects, and help from my neighbor next door, we were able to hack everything together relatively well. Progress with the project can be found on this blog under my posts: Tangible Interactions at UW.


Storyboard sketch of a farmer's field
Storyboard sketch showing a farmer checking soil nutrients
Brainstorming Ideas

User flow