The STM32F031G4U6TR: With 16 KB of program memory and 4 KB of SRAM, this part targets lean firmware stacks — bootloader plus a single control loop or a simple protocol stack (I²C, SPI, UART). The 4 KB RAM is organized as 4K x 8; if your application needs a large frame buffer or multiple DMA buffers, budget carefully. The Flash is 16K x 8, enough for a modest application with a few peripheral drivers.
Industrial temperature and active lifecycle
The 23 I/O lines in a 28-pin package leave a high ratio of usable pins to package size — useful when you need several sensor inputs and a PWM output in a small footprint.