ST32G031 - M0+ ARM Cortex-M Processor, being used to drive 9 LED display
Reference Manual https://www.st.com/resource/en/reference_manual/rm0444-stm32g0x1-advanced-armbased-32bit-mcus-stmicroelectronics.pdf Programming Manual https://www.st.com/resource/en/programming_manual/pm0223-cortexm0-programming-manual-for-stm32l0-stm32g0-stm32wl-and-stm32wb-series-stmicroelectronics.pdf Product Specification https://www.st.com/resource/en/datasheet/stm32g031k8.pdf Pinout https://os.mbed.com/platforms/ST-Nucleo-G031K8/