Scratch scratch scratch... Are those rats? Better build a robot to go investigate!
Matt has rats! Or, at least he thinks there is some kind of rodent scurrying around under his house. Unfortunately, he lives in a house without enough space underneath it to crawl in and see what's going on. Luckily, Matt is a bit of a wiz with electronics and decided to create something to scope out the area for him.
The rodent chaser in all its glory.
Having a 3D printer at his disposal, Matt set out to design a quick and easy set of pieces to put this idea into action. He designed a chassis that would hold two geared motors for the drive as well as the battery and electronics. The steering would be done "tank style" with one geared motor slowing or reversing to alter the direction.
The surface he planned on traversing was quite sandy, so he knew he needed to print some wheels with considerable traction. As you can see in the picture above, he didn't mess around -- those wheels have some serious grip! The ability to 3D-print them to simply slide right onto the gear motors must have been extremely convenient.
For the brains of the project, he chose the NETduino, an Arduino-compatable board that runs .NET. He's added a Bluetooth module, which allows him to connect with his Windows phone for sending commands to the NETduino. All of the code for this module, as well as a tutorial on getting the communication going and the code for the phone side of things, are located on his website.
You may be looking at that picture and wondering where the camera is. Matt points out that it was just easier for him to simply put another one of his phones on the car with an active skype session going. This gave him a live feed illuminated by those LEDs on the front of the car. Lets just hope the second phone doesn't get knocked off and stranded under the house!
There are a couple areas that he notes could be improved. His decision to use a standard 9V battery left him desiring something with a little longer life, and the four-wheel design is really not optimal for tank-style steering. Aside from those two items, it seems to have fulfilled its goal quite nicely.
— Caleb Kraft, Chief Community Editor, EE Times