Circuit Playground, Adafruit's multi-faceted experimenter board, may be used in many of the maker projects on the Adafruit Learning System and other tutorials on the Internet. This project extends Circuit Playground into the field of robotics.
With this project, you can make a robot with Circuit Playground that is low cost, easy to build and program. The techniques used are applicable to using continuous servos, sound processing, and robotics techniques.
There are two general methods of controlling robots: via a set of wires from a person to the robot or wirelessly in some fashion. While Circuit Playground contains a plethora of capabilities, a wireless radio is (currently) not onboard. Looking at the input sensors shows two which might allow non-wired control: the light sensor and the sound sensor. The light sensor could be a challenge to use as a control, especially in bright light. I believe there is more flexibility with the microphone.
At present, use of a Alexa/Siri type voice control system takes more processing power than is available on the Circuit Playground's ATmega 32u4 microcontroller. Circuit Playground is very able to listen for tones at certain frequencies with the capabilities built into the Circuit Playground software library.
This project is intended to be educational, so there is more detail on how the various parts of the project work. This includes optimal sound values for controlling the robot and how to set the servo motors for no movement. The data gathered in those steps will be used in building the final robot.