OpenBCI – Research grade EEG put together by an ad-hoc community. OpenBCI is a powerful Arduino compatible open source hardware design. Prices range from $350 – $1,100 depending on how much you can print and assemble yourself. The current OpenBCI headset uses 10 gold electrodes.
There is some potential for the Muse and Emotiv brands of EEG headbands to be used for DIY brain control interfaces. These headbands are in the $250 – $800 range. Muse has some (1) (2) github Arduino oriented projects. There is an unmaintained python library for Emotiv that was reverse engineered to work with a Raspberry Pi or BeagleBone Black.
Eink, E-paper, Think Ink – Collin shares six segments pondering the unusual low-power display technology that somehow still seems a bit sci-fi – http://adafruit.com/thinkink
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.