64 KB Flash, 80 MHz Cortex-M4 — the mid-density sweet spot
The STM32L412R8T6 is an ARM Cortex-M4 32-bit MCU in the STM32L4 series, running at 80 MHz with 64 KB Flash and 40K x 8 RAM. The 64-LQFP package provides 52 I/O.
Supply and temperature — single-cell Li-ion friendly
Brown-out detect and reset are on-chip, so an external supervisor isn't required for basic power-fail handling.
Peripheral mix — Quad SPI, USB, and multiple serial buses
DMA is available across all major peripherals, so the CPU isn't stalled moving data from the ADC or serial buffers. No USB OTG is listed in the connectivity set — the USB peripheral is device-only.