Arduino boards have helped revolutionize the amazing things that normal people can do with technology. However, there are now much more powerful alternatives to the ATmega328 chip at the heart of the Uno and other similar devices. For their part, Arduino has attempted to keep up with technology trends with their line of MKR products, which boast the SAM D21 Cortex-M0+ microcontroller and a variety of interesting additional features.
On the other hand, a minimal device based on this processor isn’t that difficult to make, as David Johnson-Davies shows in this “Minimal ATSAMD21 Computer.” In his Technoblogy post, he outlines the components you’ll need to construct your own SAM D21 computer on a breadboard (or otherwise), including a crystal, USB breakout, and a number of capacitors. He also took advantage of a useful breakout from Adafruit, which breaks out QFT or QFN chips on a board that ends up looking very similar to an Arduino Nano.
Beyond simply sticking the proper parts on a breadboard, you’ll need to install a bootloader as well if you want to program the device over USB using the Arduino IDE. This can mean burning one with Atmel Studio and a programmer, or he even outlines two ways to take care of this task using the Arduino IDE and an Arduino.
UPDATE: Johnson-Davies has now created another version of the computer using the larger 48-pin SAM D21G.