Diff: ChainableLED.cpp

Revision:

0:24631ceaa38a

Child:

1:50d0a66599e1

diff -r 000000000000 -r 24631ceaa38a ChainableLED.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ChainableLED.cpp	Fri Aug 02 08:05:28 2013 +0000
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2013 Seeed Technology Inc.
+ * Copyright (C) 2012 Paulo Marques (pjp.marques@gmail.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of 
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all 
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/* Information about the P9813 protocol obtained from:
+ * http://www.seeedstudio.com/wiki/index.php?title=Twig_-_Chainable_RGB_LED
+ *
+ * HSB to RGB routine adapted from:
+ * http://mjijackson.com/2008/02/rgb-to-hsl-and-rgb-to-hsv-color-model-conversion-algorithms-in-javascript
+ *
+ * This library is ported from Arduino to mbed
+ */
+
+
+// --------------------------------------------------------------------------------------
+
+#include "ChainableLED.h"
+
+// Forward declaration
+float hue2rgb(float p, float q, float t);
+
+// --------------------------------------------------------------------------------------
+
+ChainableLED::ChainableLED(PinName clk_pin, PinName data_pin, unsigned int number_of_leds) :
+    _clk_pin(clk_pin), _data_pin(data_pin)
+{
+    _num_leds = number_of_leds;
+    
+    for (uint8_t i=0; i<_num_leds; i++)
+        setColorRGB(i, 0, 0, 0);
+}
+
+ChainableLED::~ChainableLED()
+{
+}
+
+// --------------------------------------------------------------------------------------
+
+void ChainableLED::clk(void)
+{
+    _clk_pin = 0;
+    wait_us(_CLK_PULSE_DELAY);
+    _clk_pin = 1;
+    wait_us(_CLK_PULSE_DELAY);
+}
+
+void ChainableLED::sendByte(uint8_t b)
+{
+    // Send one bit at a time, starting with the MSB
+    for (uint8_t i=0; i<8; i++)
+    {
+        // If MSB is 1, write one and clock it, else write 0 and clock
+        if ((b & 0x80) != 0)
+            _data_pin = 1;
+        else
+            _data_pin = 0;
+            
+        clk();
+
+        // Advance to the next bit to send
+        b <<= 1;
+    }
+}
+ 
+void ChainableLED::sendColor(uint8_t red, uint8_t green, uint8_t blue)
+{
+    // Start by sending a uint8_t with the format "1 1 /B7 /B6 /G7 /G6 /R7 /R6"
+    uint8_t prefix = 0xC0;
+    if ((blue & 0x80) == 0)     prefix|= 0x20;
+    if ((blue & 0x40) == 0)     prefix|= 0x10; 
+    if ((green & 0x80) == 0)    prefix|= 0x08;
+    if ((green & 0x40) == 0)    prefix|= 0x04;
+    if ((red & 0x80) == 0)      prefix|= 0x02;
+    if ((red & 0x40) == 0)      prefix|= 0x01;
+    sendByte(prefix);
+        
+    // Now must send the 3 colors
+    sendByte(blue);
+    sendByte(green);
+    sendByte(red);
+}
+
+void ChainableLED::setColorRGB(unsigned int led, uint8_t red, uint8_t green, uint8_t blue)
+{
+    // Send data frame prefix (32x "0")
+    sendByte(0x00);
+    sendByte(0x00);
+    sendByte(0x00);
+    sendByte(0x00);
+    
+    // Send color data for each one of the leds
+    for (uint8_t i=0; i<_num_leds; i++)
+    {
+        if (i == led)
+        {
+            _led_state[i*3 + _CL_RED] = red;
+            _led_state[i*3 + _CL_GREEN] = green;
+            _led_state[i*3 + _CL_BLUE] = blue;
+        }
+                    
+        sendColor(_led_state[i*3 + _CL_RED], 
+                  _led_state[i*3 + _CL_GREEN], 
+                  _led_state[i*3 + _CL_BLUE]);
+    }
+
+    // Terminate data frame (32x "0")
+    sendByte(0x00);
+    sendByte(0x00);
+    sendByte(0x00);
+    sendByte(0x00);
+}
+
+void ChainableLED::setColorHSB(unsigned int led, float hue, float saturation, float brightness)
+{
+    float r, g, b;
+    
+//     constrain(hue, 0.0, 1.0);
+//     constrain(saturation, 0.0, 1.0);
+//     constrain(brightness, 0.0, 1.0);
+
+    if(saturation == 0.0)
+    {
+        r = g = b = brightness;
+    }
+    else
+    {
+        float q = brightness < 0.5 ? 
+            brightness * (1.0 + saturation) : brightness + saturation - brightness * saturation;
+        float p = 2.0 * brightness - q;
+        r = hue2rgb(p, q, hue + 1.0/3.0);
+        g = hue2rgb(p, q, hue);
+        b = hue2rgb(p, q, hue - 1.0/3.0);
+    }
+
+    setColorRGB(led, (uint8_t)(255.0*r), (uint8_t)(255.0*g), (uint8_t)(255.0*b));
+}
+
+// --------------------------------------------------------------------------------------
+
+float hue2rgb(float p, float q, float t)
+{
+    if (t < 0.0) 
+        t += 1.0;
+    if(t > 1.0) 
+        t -= 1.0;
+    if(t < 1.0/6.0) 
+        return p + (q - p) * 6.0 * t;
+    if(t < 1.0/2.0) 
+        return q;
+    if(t < 2.0/3.0) 
+        return p + (q - p) * (2.0/3.0 - t) * 6.0;
+
+    return p;
+}