Above the frozen ocean, Antarctica can be eerily quiet. Gusts of wind are often all one hears. Below, though, the Southern Ocean is a living soundscape dominated by Weddell seals. These pinnipeds typically emit high-pitched pings that sound like laser guns in a science-fiction movie. But that is not their entire repertoire. Research now reveals that a significant portion of their calls are at ultrasonic frequencies, high pitches well beyond the 20-kilohertz limit of most human hearing.
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.