The microcontroller used is the ARM Cortex-M3, which is part of the STM32L1 series. It features a single-core, 32-bit design with a clock speed of 32 MHz and includes 256 KB of flash memory organized as 256 K x 8 bits. This chip comes in a 48-pin LQFP (Leadless Quad Flat Pack) package measuring 7x7 mm.