A few months ago, UncleStem built a completely functional 7:1 scale Arduino UNO Rev3 development board. That was a big hit, for obvious reasons. But what can you do with an Arduino of that size? The answer is: create a matching 7:1 scale turtle robot for it to control.

This is a great pairing, because turtle robots are often the first big projects that new Arduino users tackle — usually soon after blinking an LED. Just like with the oversized Arduino, UncleStem wanted to honor that tradition with the power of enlargement. 

He started by building a classic example of a normal-sized turtle robot from a kit. That is, of course, controlled by an UNO Rev3. The Arduino turns the two motors through an L298N dual H-bridge driver and avoids obstacles using an ultrasonic sensor. The ultrasonic sensor is on a servo-actuated panning mount, so it can “look around” for the optimal path when it runs into anything. The frame is just a piece of laser-cut transparent acrylic.

With that as a reference, UncleStem began building the scaled-up version. Most of the components are 3D-printed shells that match the mundane originals, but that contain the closest functional matches. For example, the drive motors are 12-24V geared units intended for kids’ ride-on vehicles. The “L298N” hides a pair of high-power 300W drivers suitable for those motors. A laser-cut plywood panel replicates the L298N’s PCB.

UncleStem progressed through all of the components in the same manner. He even made giant jumper cables to connect the components together.

The best part is that the mega turtle robot functions just like the original. It looks around with its ultrasonic sensor to find ways around obstacles, which is really fun to watch.