Circuit Playground Classic

Overview

The Circuit Playground Classic is Adafruit's all-in-one educational microcontroller board built around the ATmega32u4 running at 8 MHz and 3.3V. It packs an astonishing array of hardware into a circular 2-inch (50.6mm) board designed to be worn, clipped, and coded by beginners and experts alike.

The board features 10 mini NeoPixel RGB LEDs arranged in a ring, a LIS3DH triple-axis accelerometer with tap and free-fall detection, a MEMS microphone, a mini magnetic speaker, a phototransistor for light sensing, an NTC thermistor for temperature, and two push buttons plus a slide switch — all without needing any wiring.

All eight I/O pads around the perimeter are alligator-clip friendly and support capacitive touch input, making it ideal for craft and wearable projects. The pads also offer analog input, PWM output, and hardware I2C and UART for connecting external sensors and modules.

The Circuit Playground Classic is programmable via Arduino IDE and works with Adafruit's CircuitPlayground library, providing easy access to all onboard sensors. It was designed as the original version of the Circuit Playground platform before the Express model introduced CircuitPython support.