.. highlight:: cpp

Led
===
All boards come with an on-board RGB LED.  The RGB LED is able to light up the board in various colors and patterns.

Users can control the LED with the functions in the `led.h <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html>`_ header file.

Setting Patterns
----------------
An led pattern is represented by the `MblMwLedPattern <https://mbientlab.com/docs/metawear/cpp/latest/structMblMwLedPattern.html>`_ struct.  Users can 
configure every part of the pulse or load one of the preset patterns using the 
`mbl_mw_led_load_preset_pattern <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#a033cf02db3dd86ca41e4a0a2eee054d3>`_ function.  Patterns 
are written to the board with the 
`mbl_mw_led_write_pattern <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#a85e85092c649a75bf8f5a8749b7331a2>`_ function.

To remove patterns, call `mbl_mw_led_stop__and_clear <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#a34624667cd8f52bedc818a8900377c01>`_;  
this will also stop pattern playback. ::

    #include "metawear/peripheral/led.h"
    
    void set_led_pattern(MblMwMetaWearBoard* board) {
        MblMwLedPattern pattern;
    
        // Load the blink pattern
        mbl_mw_led_load_preset_pattern(&pattern, MBL_MW_LED_PRESET_BLINK);
    
        // Write the blink pattern to the blue channel
        mbl_mw_led_write_pattern(board, &pattern, MBL_MW_LED_COLOR_BLUE);
    }

Pattern Playback
----------------
After writing patterns to the board, you can playback the pattern, similar to playing a music track, using  
`mbl_mw_led_play <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#ae6dbd4d6e272522003137c5456576aaa>`_, 
`mbl_mw_led_pause <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#aba0961b6734c8dda2b6d155814d0089c>`_, and 
`mbl_mw_led_stop <https://mbientlab.com/docs/metawear/cpp/latest/led_8h.html#a25f9c37cf33bf43cedf04535e76c5b7b>`_. ::

    #include "metawear/peripheral/led.h"
    
    void start_pattern(MblMwMetaWearBoard* board) {
        // Start playing the programmed patterns
        mbl_mw_led_play(board);
    }