We’re going to be doing a more thorough round-up of some of the other amazing entries in the Make: Robot Build, but we wanted to give a special shout-out to Jasmine (11) and her dad Shane’s truly unique project, Tortellini the Turtle Bot. As we said, the judging was really hard because we had so many impressive entries. Tortellini came in 4th, only by a tenth of a point!
There are so many things to like about Tortellini, from the thermoformed, very turtle-looking, CD shell, to the unique walking gate, to the vision system (I get a chuckle every time Tortellini yanks his head back and forth). Check out the YouTube video of Tortellini doing his robo-tortoise traversing of an obstacle course. Here are some technical details from the contest submission form:
Using a mini-CD as a base, four gear motors actuate the legs. The motors only are operated in the forward directly allowing the use of a single quad H-Bridge. The walking motion is realized by a offset rotation on top and a sliding pivot point in the middle of the leg. Rubber grommets were used as feet to increase traction and decrease noise. Due to the lack of a 3.3V H-bridge, 2 Li-ion batteries were used and regulated to 5 V with a 7805. Four photo reflector sensors are used to note top dead center for the legs to control the gait. Walking is achieved by moving diagonal pairs 180 degrees out of phase. In addition, a servo motor controls the direction of the head which has a higher power IR LED and photo transistor pair.
A PIC 16F690 is used for contol. Four Digital Outputs control individual PWM for the motors through a 500 usec interrupt routine. This is also used to create the pulse for servo motor which is the 5th output. To save I/Os, all sensors are powered continually from the 5V regulated supply. This, along with the decision to only run the motors forward, saved 10 outputs and a driver chip. A six pin header was added to be able to program the micro by removing the top board with a Pickit 2.
Heartfelt congrats to Jasmine and Shane for such an incredible job. If you guys do any more robot builds, or other tech projects together, please send them our way. We’re so impressed by Jasime and expect great things from her! Keep in touch.
The Make: Robot Build