Created as a free solid CAD tool related to their much more expensive flagship Autodesk Inventor software, 123D Design offers a hobbyist introduction to CAD tools that makes it really easy to create things like enclosures, cases, and simple mechanical models without the steeper learning curve of the more advanced apps. There is a premium option that offers more tools and export formats — including creating 2D plans / documentation for models and access to a larger 123D Content Library for prebuilt parts.
They have created a number of helpful tutorial videos to help users get started here.
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.