Interrupts on STM32 MCUs come in two flavors: internal and external. Both types of interrupts use the same core peripheral in the Cortex-M core: the Nested Vectored Interrupt Controller, or NVIC.

TouchGFX, as it is called, “is ready to use with STM32 microcontrollers and includes a C++ framework that enables the user-interface code to occupy as little as 10kbyte SRAM and 20kbyte flash memory,” ...

We’ll be using the STM32F042 as the target MCU, but other STM32 families are rather similar from an I2C perspective. We’ll also use CMSIS-style peripheral and register references.