.. highlight:: java

Led
===

The `Led <https://mbientlab.com/docs/metawear/android/2/com/mbientlab/metawear/module/Led.html>`_ module interacts with the on-board LED.  We have a `blog post <http://projects.mbientlab.com/programming-led-patterns-on-the-metawear-board/>`_ that takes a more in depth look at the module.  While it is for the older APIs, the attributes are still pertinent for the updated Led class.

Setting Patterns
----------------

LED patterns function as a pulse with four main parameters to modify: rise time, high time, fall time, and duration.  These parameters are modified using the `ColorChannelEditor <https://mbientlab.com/docs/metawear/android/2/com/mbientlab/metawear/module/Led.ColorChannelEditor.html>`_ and each color channel (rgb) is configured independent of the other colors, allowing you to program different patterns for each color.

::

    import com.mbientlab.metawear.module.Led;
    
    // Set the blue channel to turn on for 5 seconds
    mwBoard.getModule(Led.class).configureColorChannel(Led.ColorChannel.BLUE)
        .setRiseTime((short) 0).setPulseDuration((short) 1000)
        .setRepeatCount((byte) 5).setHighTime((short) 500)
        .setHighIntensity((byte) 16).setLowIntensity((byte) 16)
        .commit();

Pattern Playback
----------------

Controlling the pattern playback is handled with the `play <https://mbientlab.com/docs/metawear/android/2/com/mbientlab/metawear/module/Led.html#play(boolean)>`_, `pause <https://mbientlab.com/docs/metawear/android/2/com/mbientlab/metawear/module/Led.html#pause()>`_, and `stop <https://mbientlab.com/docs/metawear/android/2/com/mbientlab/metawear/module/Led.html#stop(boolean)>`_ methods.  The stop method also functions to clear the programmed patterns and the play method has an autoplay feature that will play any pattern as soon as it is programmed. ::

    import com.mbientlab.metawear.module.Led;
    
    Led ledModule= mwBoard.getModule(Led.class);
    
    // Immediately play a pattern when it is programmed,
    // play any patterns already programmed
    ledModule.play(true);
    
    // Stop playing patterns and clear all programmed patterns
    ledModule.stop(true);