The demo takes advantage of the RSL15-EVB evaluation kit that ties into a smartphone app. The RSL10 is used in an energy-harvesting board that can send switch status via Bluetooth without needing a battery.
The RSL15 is built around the latest Arm Cortex-M33 with TrustZone and secure-boot support (Fig. 2). The Bluetooth Low Energy 5.2 front-end is built-in and it works well with a low-cost PCB antenna.