This wearable development board can be used on textiles as well as sensors actuators and similarly mounted power supplies.
Features

100% compatible with Arduino Liliypad

Specifications

microcontroller: ATmega32U4
operating voltage: 2.7 5.5 VDC
input voltage: 2.7 5.5 VDC
digital I/O pins: 9
PWM channels: 4
analogue input channels: 4
DC current per I/O pin: 40 mA
flash memory: 32 KB (of which 4 KB used by bootloader)
SRAM: 2.5 KB
EEPROM: 1 KB
clock speed: 8 MHz
diameter: 50 mm