Universal Windows® Apps with XAML and C# Unleashed

Communicating with the Device

You don’t write and read data directly to/from a service. Instead, you do this with one of a service’s characteristics. A characteristic represents a single logical data value. For example, a blood pressure service may expose BloodPressureMeasurement, BloodPressureFeature, IntermediateCuffPressure, and BodySensorLocation characteristics. Each characteristic is identified by a Guid, and 21 well-known characteristics are represented as static Guid properties on the GattCharacteristicUuids class.

A service might not only support multiple characteristics, but it may have more than one instance of each characteristic! Therefore, to get a characteristic, you must call GattDeviceService’s GetCharacteristics (plural) method ...