BLE Advertising sample application

Dependents:   X_NUCLEO_IDB0XA1

This example shows how to advertise a value of battery service data. The battery value is simulated. The battery level is a percentage, with 100% being a fully charged battery and 0% being a fully drained battery. The level starts at 50% and drains every second second, until it hits 10% when it jumps to 100% and continues draining.