Bluetooth® Low Energy is really good at transferring low amounts of data and using very low power, when in standby mode & awaiting a connection. Bluetooth® Classic is significantly
faster at transferring larger volumes of data such as time waveforms. Machine sentry uses the low energy Bluetooth® to advertise some key information without connecting. This includes:
· The battery level
· The data and time of the last reading
collected by the sensor
· Whether the battery has been changed
· The signal strength.
This allows the Android application to decide quickly if it needs to connect to the sensor without having to connect first which would be the case in if classic was used. Using Bluetooth® Classic for the data transfer allows us to transfer much faster than if we did everything via low energy. Typically a Classic Bluetooth® connection can transfer 5 to 10 measurements (fulltime waveforms) per second, where as a low energy connection would take at least 15 seconds per measurement.