TODO
Little Hippo is a small, inexpensive, autonomous robot capable of navigating around obstacles. The system was built using a RC car from Walgreens, a Parallax PING ultrasonic sensor, a L293DNE H-bridge for the motor driver circuit, and an Arduino board.
The look of the rover revolves around a small bottle of apple juice I had one day, it reminded me of the heads of the LEGO characters so I decided to use that to give Little Hippo a bit of a personality.
I flipped the bottle upside down and mounted it on top of a small servo, then I incorporated the PING sensor in the front in a way that resembles a pair of eyes. This makes up the obstacle detection and avoidance system. Little Hippo can “look” front, left, and right to determine the presence of an obstacle and then make a decision about what to do.
For the main drive train, Little Hippo uses the functional part of a Walgreens RC car, I got it for close to $10, removed it’s chasis and hooked its motors to a pretty simple DC motor driver built using a L293 H-bridge (any H-bridge would do). One side controls the DC motor for steering and the other the forward and reverse drive.
Finally, Little Hippo’s brains are made up of an Arduino board. The board receives the input from the PING sensor and takes care of controlling the servo that turns the head around as well as the drive train for the robot. Eventually the Arduino will be replaced by an ATMega chip running the Arduino bootloader (it’s cheaper and leaves the board available for future projects).
More to come soon…