64 MHz Cortex-M0+ in a 20-pin TSSOP
The STM32G031F4P6: With 16 KB of flash and 8 KB of SRAM, the memory budget fits compact control firmware — a single UART bootloader plus a state machine leaves roughly 6 KB of flash for application code after the HAL and RTOS overhead, so the target application should be lean or use the DMA engine to offload peripheral data movement.
Peripheral set and I/O allocation
18 general-purpose I/O pins are multiplexed with the peripheral functions — I²C, SPI, UART/USART with LIN and IrDA support, plus a SmartCard interface — so the pin count forces trade-offs: enabling two serial interfaces and the 12-bit SAR ADC's 17 channels consumes most of the available pins, leaving few for discrete GPIO. The 17-channel 12-bit SAR ADC samples at up to 2 MSPS in single-shot mode — sufficient for three-phase current sensing in a low-end motor drive or for reading a bank of thermistors in a temperature-logging array. DMA, PWM, and watchdog timer peripherals are on-chip — the DMA offloads ADC result transfers and UART data movement from the CPU, leaving the Cortex-M0+ free to run the control loop.
The base product number STM32G031 covers the full family, so if a higher-memory variant is needed later, the pin-compatible STM32G031K8 (64 KB flash) drops into the same 20-TSSOP footprint without a board spin. ROHS3 compliant per — no substance restrictions that would block EU or California market entry.