RGBLED.cpp

00001 /*
00002  * Copyright (C) 2013 Seeed Technology Inc.
00003  * Copyright (C) 2012 Paulo Marques (pjp.marques@gmail.com)
00004  *
00005  * Permission is hereby granted, free of charge, to any person obtaining a copy of 
00006  * this software and associated documentation files (the "Software"), to deal in
00007  * the Software without restriction, including without limitation the rights to
00008  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
00009  * the Software, and to permit persons to whom the Software is furnished to do so,
00010  * subject to the following conditions:
00011  * 
00012  * The above copyright notice and this permission notice shall be included in all 
00013  * copies or substantial portions of the Software.
00014  * 
00015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
00017  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
00018  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
00019  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
00020  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00021  */
00022 
00023 /* Information about the P9813 protocol obtained from:
00024  * http://www.seeedstudio.com/wiki/index.php?title=Twig_-_Chainable_RGB_LED
00025  *
00026  * HSB to RGB routine adapted from:
00027  * http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
00028  *
00029  * This library is ported from Arduino to mbed
00030  */
00031 
00032 
00033 // --------------------------------------------------------------------------------------
00034 
00035 #include "RGBLED.h"
00036 
00037 // Forward declaration
00038 float hue2rgb(float p, float q, float t);
00039 PwmOut          PWMR(P0_11);
00040 PwmOut          PWMG(P0_9);
00041 PwmOut          PWMB(P0_10);
00042 // --------------------------------------------------------------------------------------
00043 
00044 ChainableLED::ChainableLED(PinName r_pin, PinName g_pin, PinName b_pin,unsigned int number_of_leds) :
00045     _r_pin(r_pin), _g_pin(g_pin),_b_pin(b_pin)
00046 {
00047     _num_leds = number_of_leds;
00048     
00049 
00050     for (uint8_t i=0; i<_num_leds; i++)
00051         setColorRGB(i, 0, 0, 0);
00052 }
00053 
00054 ChainableLED::~ChainableLED()
00055 {
00056 }
00057 
00058 // --------------------------------------------------------------------------------------
00059 
00060 
00061  
00062 void ChainableLED::sendColor(uint8_t red, uint8_t green, uint8_t blue)
00063 {
00064     //control the RGB LED by PWM
00065     PWMR = (float)red/255;
00066     PWMG = (float)green/255;
00067     PWMB = (float)blue/255;
00068     
00069 }
00070 
00071 void ChainableLED::setColorRGB(unsigned int led, float red, float green, float blue)
00072 {
00073     sendColor(0xff-red, 0xff-green, 0xff-blue );    
00074 }
00075 
00076 void ChainableLED::setColorHSB(unsigned int led, float hue, float saturation, float brightness)
00077 {
00078     float r, g, b;
00079     
00080     if(saturation == 0.0)
00081     {
00082         r = g = b = brightness;
00083     }
00084     else
00085     {
00086         float q = brightness < 0.5 ? 
00087             brightness * (1.0 + saturation) : brightness + saturation - brightness * saturation;
00088         float p = 2.0 * brightness - q;
00089         r = hue2rgb(p, q, hue + 1.0/3.0);
00090         g = hue2rgb(p, q, hue);
00091         b = hue2rgb(p, q, hue - 1.0/3.0);
00092     }
00093 
00094     setColorRGB(led, (uint8_t)(255.0*r), (uint8_t)(255.0*g), (uint8_t)(255.0*b));
00095 }
00096 
00097 // --------------------------------------------------------------------------------------
00098 
00099 float hue2rgb(float p, float q, float t)
00100 {
00101     if (t < 0.0) 
00102         t += 1.0;
00103     if(t > 1.0) 
00104         t -= 1.0;
00105     if(t < 1.0/6.0) 
00106         return p + (q - p) * 6.0 * t;
00107     if(t < 1.0/2.0) 
00108         return q;
00109     if(t < 2.0/3.0) 
00110         return p + (q - p) * (2.0/3.0 - t) * 6.0;
00111 
00112     return p;
00113 }