.. highlight:: cpp

Color Detector
==============
The light sensor works by shining a white light at an object and then recording the reflected colour. It can also record the intensity of the reflection (brightness). 
Through red, green and blue colour filters the photodiode converts the amount of light to current.

MetaEnvironment boards come equipped with a `TCS34725 <http://ams.com/eng/Products/Light-Sensors/Color-Sensors/TCS34725>`_ color detector.  Enums and 
functions for interacting with this sensor are defined in the 
`colordetector_tcs34725.h <https://mbientlab.com/docs/metawear/cpp/latest/colordetector__tcs34725_8h.html>`_ header file.

Configuration
-------------
The `TCS34725 <http://ams.com/eng/Products/Light-Sensors/Color-Sensors/TCS34725>`_ sensor has 2 configurable parameters that affect the data range and 
resultion: 

================  ============================================
Parameter         Description
================  ============================================
Gain              Analog signal scale
Integration Time  Amount of time spent to aggregate adc values
================  ============================================

Afer you configure the API with your desired settings, call 
`mbl_mw_cd_tcs34725_write_config <https://mbientlab.com/docs/metawear/cpp/latest/colordetector__tcs34725_8h.html#a78084a7cc57f0a56eb5b338aca732138>`_ 
to write the changes to the detector. ::

    #include "metawear/sensor/colordetector_tcs34725.h"
    
    void colordetector_config(MblMwMetaWearBoard* board) {
        // set analog gain to 16x
        mbl_mw_cd_tcs34725_set_gain(board, MBL_MW_CD_TCS34725_GAIN_16X);
    
        // set integration time to 4.8ms
        mbl_mw_cd_tcs34725_set_integration_time(board, 4.8f);
    
        // write the configuration to the sensor
        mbl_mw_cd_tcs34725_write_config(board);
    }

The MetaWear board also comes with an illuminator LED which can be used to provide additional light when reading the color.  To enable the LED, call 
`mbl_mw_cd_tcs34725_enable_illuminator_led <https://mbientlab.com/docs/metawear/cpp/latest/colordetector__tcs34725_8h.html#abdd816e83bbc3a550b5ba6a50d803729>`_ before writing the configuration changes.

Color ADC
---------
To retrieve color adc, call 
`mbl_mw_datasignal_read <https://mbientlab.com/docs/metawear/cpp/latest/datasignal_8h.html#a0a456ad1b6d7e7abb157bdf2fc98f179>`_ with a color adc data 
signal.  

Users can use the timer functions (see :doc:`timer` section) 

to schedule periodic reads.  ::

    #include "metawear/core/datasignal.h"
    #include "metawear/core/types.h"
    
    void colordetector_adc_stream(MblMwMetaWearBoard* board) {
        auto adc_signal= mbl_mw_cd_tcs34725_get_adc_data_signal(board);
    
        mbl_mw_datasignal_subscribe(adc_signal, [](const MblMwData* data) -> void {
            // Cast value to MblMwTcs34725ColorAdc*
            auto color_adc = (MblMwTcs34725ColorAdc*) data->value;
            printf("{clear: %d, red: %d, green: %d, blue: %d}", color_adc->clear, 
                    color_adc->red, color_adc->green, color_adc->blue);
        });
        mbl_mw_datasignal_read(adc_signal);
    }