Meet Stompy, the Arduino quadruped robot.
Most of the quadrupeds I’ve seen use “insect” type legs, but I wanted to try one with “mammal” type legs. The result was Stompy, a quadruped using eight servos, with each leg consisting of a hip joint and an ankle joint (no knee). Stompy uses a “trot” type gait where the front right leg is synchronized with the back left leg and these two limbs move in antiphase with the other two limbs. The result is a stomping type of walk, but it gets the job done. Controlling all the servos requires eight PWM pins and standard Arduinos only have six, so I decided to use an Arduino Mega. Stompy uses an IR distance sensor to keep from bumping into things and is capable of autonomous movement.