I added anAdafruit 128×64 graphical OLED display, Particle Argon WiFi μC, LiPo battery pack, and tube voltage monitoring circuit. It features an AD8244 high-input-impedance buffer and a 1 GΩ/3.9 MΩ voltage divider to connect to an ADC pin on the Argon.
I converted some classic Mac fonts to use with the Adafruit_GFX (graphics display) library—Espy Sans, Chicago, and Geneva—for the ultimate UI bitmap font style.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.