Cortex-M0+ core, 32 MHz ceiling, 64-LQFP
The STM32L051R8T6TR is an STM32L0 series MCU built around an ARM Cortex-M0+ core running at 32 MHz. That 32 MHz ceiling determines the throughput for control loops, sensor polling, and serial protocol handling — budget it against your interrupt latency and DMA transfer times.
Flash, RAM, and EEPROM headroom
64 KB of on-chip flash and 8 KB of SRAM are the firmware budget. The flash holds the application image plus any constant data; the 8 KB SRAM covers the stack, heap, and DMA buffers. A 2 KB embedded EEPROM stores calibration constants or configuration parameters without needing an external serial EEPROM — useful for sensor offset tables or production-line trim values that survive power cycles.
Peripherals and connectivity
On-chip peripherals include a 16-channel 12-bit ADC, DMA, PWM timers, and a brown-out detect/reset. For serial interfaces you get I²C, SPI, UART/USART, and IrDA — enough to talk to most MEMS sensors, external ADCs, or radio modules without bit-banging. The internal oscillator saves an external crystal for applications that can tolerate the factory-trimmed accuracy.
Temperature grade and compliance
The device is marked Active in production and is ROHS3 compliant.