The STM32WB implements a Cortex-M4 with a dedicated Cortex-M0+ to run a Bluetooth BLE stack. This line provides a lot of integration, from large flash memory and RAM to mixed-signal analog peripherals, including touch sensors and small segment LCDs. Various security features, such as crypto algorithms and a random number generator, are also present. Since FCC certification is required for products using this family of devices, they will make the most sense for high volume applications.

With a wide range of MCUs to choose from, STM probably has something we can use to experiment with an RTOS! It's time to move on to selecting a development board to use.