There are many challenges to being a middle school teacher, and while some may never be solved by technology, Jason Erdreich (AKA “Mr. E”) decided he could at least make a device to help him keep his pencils secure. As he puts it, he chose to solve this minor problem “in the most complicated way possible.”
What he came up with is a pencil holder that holds 10 pencils in place, and senses them with LDRs. When one is removed, an Arduino Uno commands the RGB lighting in the unit to go from green to red. Along with this, it actuates a very large “return pencils” sign on top of a safety glasses locker, making it obvious that writing utensils need to be returned.
The pencil protector features a custom PCB that is designed as a vector drawing in Adobe Illustrator, then exported and converted for manufacturing on the class CNC router. As Erdreich teaches technology, engineering, and design, this makes a great showcase for what one can do when the proper electromechanical skills are combined. It even features a clear acrylic front face to show its inner workings.
Check out the video below for a short demonstration of the system in action!