32 MHz Cortex-M0+ — the low-power workhorse
It runs at 32 MHz and integrates 192 KB of Flash program memory, 20 KB of SRAM, and a dedicated 6 KB EEPROM block — enough to hold a modest application stack and persistent configuration without external storage. An on-chip 12-bit ADC with 16 channels and a dual 12-bit DAC cover most sensor and control-loop needs without external converters.
Supply voltage and battery operation
A single lithium cell (3.0 V – 4.2 V) or two series alkaline cells (1.8 V – 3.0 V) can power the MCU without a boost regulator, saving board space and quiescent losses.
Memory and peripheral mix
The 192 KB Flash is partitioned for firmware and bootloader staging; the 20 KB SRAM handles moderate data buffers, and the 6 KB true EEPROM eliminates the need for Flash-emulation wear-leveling in the application layer. The 84 GPIOs in the 100-LQFP package give headroom for a parallel LCD interface (the LCD peripheral is listed), a keypad matrix, and multiple chip selects without bit-banging.