Having a 32-bit processor with lots of memory running at 40 or 50 MIPS is a game changer compared to, say, a traditional Arduino ... into a breadboard, but looking back the simple circuit would ...

This is modeled after the Lilypad hardware, and fits nicely on top of the plastic case of the microcontroller, allowing it to be used in a breadboard ... is a full Arduino, but the circuit board ...