Using the Mobile Sensor API

To receive data measurements in a MIDlet, you need to identify the correct sensor and open a connection to that sensor. Sensors are identified by their URL, which starts with the sensor: prefix. A sensor connection is opened with the javax.microedition.io.Connector.open method.

Figure: Opening a sensor connection

An opened sensor can function in two modes:

• In synchronous mode, the MIDlet polls the sensor with the SensorConnection.getData method to receive the requested data at the necessary intervals.

• In asynchronous mode, the MIDlet listens to DataListener.dataReceived notifications from the sensor. Listening can start either when the sensor connection is opened or only when certain preset conditions are met.

After using a sensor, you need to close its sensor connection.

Figure: Lifecycle for an asynchronous sensor connection

For more details, see the following sections:

• Finding and identifying sensors

• Opening a sensor connection

• Retrieving data from a sensor

• Using data listeners

• Using condition listening

• Choosing the listening method

• Closing a sensor connection