We know one type of wearable electronics – Arduino based LilyPad. It has round shape and has only basic support circuit required to operate. Other parts come as extensions that can be sewed using conductive threads. Rayshobby LLC also work on open source wearable electronics using PIC microcontrollers.
SquareWear name already tells that its shape is square. It packs mire electronics in 1.6″x1.7″ sized board. First of all selected microcontroller is PIC18F14k50 which comes with native USB and can be programmed using HID class bootloader. Another nice feature is that board already has four MOSFETs connected to digital pins. This allows driving higher loads without additional circuits. These can be LED stripes or other high current loads. SquareWear is powered using CR2032 coin battery cell. There is an open source library available that provides high level functions to access SquareWear modules. Software can be built using MPLAB X IDE.
We recommend EasyEDA for circuit design and PCB prototype