ARM Cortex-M0+ at 32 MHz — the ultra-low-power workhorse
The STM32L081CZU6: Runs at 32 MHz with 192 KB Flash, 20 KB SRAM, and 6 KB EEPROM.
192 KB Flash + 6 KB EEPROM — memory mix for field-updatable designs
192 KB Flash (192 K x 8) and 20 KB SRAM. 6 KB EEPROM stores calibration constants without wearing Flash. 40 I/O lines in the 48-UFQFPN (7x7 mm) package.
Peripheral set and connectivity
Connectivity covers I²C, IrDA, LINbus, SPI, and UART/USART, so it talks to common sensors, displays, and transceivers without level shifters in most cases. The 13-channel 12-bit ADC is enough for reading multiple analog sensors — thermistors, potentiometers, current shunts — without an external mux. The internal reference is adequate for 8-bit accuracy; for the full 12-bit range a cleaner external reference improves INL.
The base product number is STM32L081, and the full family includes density and package variants that share the same peripheral set, so a migration to a larger Flash or different pin count stays within the same firmware base.
