Sensors

Defining sensors in a SMIL playlist is designed to be robust, future-proof, and human-readable. Below is an example for already integrated Nexmosphere sensors.

See Triggers and Interactivity for the shared trigger model (the trigger id prefix, sub-regions, condition syntax).

Using Nexmosphere sensors

Nexmosphere supports a large number of industry-grade sensors and provides a great response time.

Read More About Nexmosphere

See the Nexmosphere website for sensor hardware documentation.

You can define multiple sensors attached to the supported device.

The Nexmosphere controller is expected on serial port /dev/ttyUSB0 by default; use the serialPortDevice applet configuration option to point the player at a different port (e.g. COM3). Currently the supported sensor type is the Nexmosphere RFID antenna (type="rfid" with driver="nexmosphere"); other sensor definitions are ignored. The address option is required — a sensor without it is skipped.

<head>
    <sensors>
        <sensor type="rfid" id="rfid1" driver="nexmosphere">
            <!-- Port on Nexmosphere controller where the antenna is attached to -->
            <option name="address">004</option>
        </sensor>
        <sensor type="rfid" id="rfid2" driver="nexmosphere">
            <!-- Port on Nexmosphere controller where the antenna is attached to -->
            <option name="address">005</option>
        </sensor>
    </sensors>
</head>

Once you define sensors, you can use them for triggering playlists:

<head>
    <triggers>
        <trigger id="trigger1" condition="or">
            <condition origin="rfid1" data="1" action="picked"/>
        </trigger>
        <trigger id="trigger2" condition="or">
            <condition origin="rfid1" data="2" action="picked"/>
        </trigger>
    </triggers>

</head>

The code above will

• trigger <par begin="trigger1"> or <seq begin="trigger1">
• whenever the rfid antenna (<condition origin="rfid1" ...)
• emits an RFID tag with ID 1 (<condition ... data="1")
• was picked up (<condition ... action="picked").

Available sensors and related actions

RFID Antenna

Sensor actions:

• picked for the action when you pick up the RFID tag from the antenna
• placed for the action when you put down the RFID tag on the antenna

Both actions use the same <sensor> and <condition> shape shown above — only action (and optionally data) changes:

<trigger id="trigger1" condition="or">
    <!-- origin: reference to the <sensor id="rfid1">;
         data: the RFID tag ID you are using;
         action: the user action with the RFID tag -->
    <condition origin="rfid1" data="5" action="picked"/>
</trigger>

Every RFID tag that can be picked up or placed must be declared in a trigger condition. Note that for sensor triggers the dur attribute on the triggered playlist is ignored — use repeatCount, or let the opposite action (e.g. placed after picked) end the content.