apa102.h

00001  /*
00002 Copyright (c) 2011 Thomas Olsson.
00003 
00004 Permission is hereby granted, free of charge, to any person obtaining a copy
00005 of this software and associated documentation files (the "Software"), to deal
00006 in the Software without restriction, including without limitation the rights
00007 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008 copies of the Software, and to permit persons to whom the Software is
00009 furnished to do so, subject to the following conditions:
00010  
00011 The above copyright notice and this permission notice shall be included in
00012 all copies or substantial portions of the Software.
00013  
00014 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020 THE SOFTWARE.
00021 */
00022 
00023 #ifndef APA102_H
00024 #define APA102_H
00025 
00026 #include "mbed.h"
00027 #include "HTML_color.h"
00028 
00029 #define APA102_MAX_LEVEL 100
00030 
00031 /** APA102 class, controlling LED strips or arrays like this http://www.sparkfun.com/products/10312
00032 *
00033 * the APA102 IC's are 5V but works well connected directly to mbed IO pins.
00034 *
00035 * You need a 5V power supply capable of about 2A to light up a 32 led strip, do NOT power from mbed(usb).
00036 *
00037 * the required reset delay is a blocking wait(), it can be lowered (or set to 0) if you want to use the
00038 * time for executing code instead, data sheet says 500us but i found it need at least 800us.
00039 *
00040 * Example:
00041 * @code
00042 #include "mbed.h"
00043 #include "apa102.h"
00044 
00045 #define STRIP_LENGTH 32
00046 
00047 apa102 mystrip(p9, p10, STRIP_LENGTH);
00048 
00049 int dir=1, level=10;
00050 int rainbow[] = {0xff00ff,0xff00cc,0xff0099,0xff0066,0xff0033,0xff0000,0xff3300,0xff6600,
00051                  0xff9900,0xffcc00,0xffff00,0xccff00,0x99ff00,0x66ff00,0x33ff00,0x00ff00,
00052                  0x00ff33,0x00ff66,0x00ff99,0x00ffcc,0x00ffff,0x00ccff,0x0099ff,0x0066ff,
00053                  0x0033ff,0x0000ff,0x3300ff,0x6600ff,0x9900ff,0xcc00ff,0x9900ff,0x6600ff
00054                 };
00055               
00056 void move(void){
00057     int temp = rainbow[31];
00058     for (int x = (STRIP_LENGTH - 1) ; x > 0 ; x--) rainbow[x] = rainbow[x - 1];
00059     rainbow[0] = temp;
00060 }    
00061 
00062 void pulse(void){
00063     if(dir)
00064       {
00065       mystrip.level(level+=2);
00066       if(level >= 100)dir = 0;
00067       }
00068     else if(!dir)
00069     {
00070     mystrip.level(level--);
00071     if(level <= 5)dir = 1;    
00072     }
00073 }
00074        
00075 int main() {
00076     mystrip.level(level);
00077     while(1)
00078       {
00079       move();
00080       pulse();
00081       mystrip.post(rainbow);
00082       wait_ms(100);
00083       }
00084 }
00085 * @endcode
00086  */
00087 class apa102 
00088 {
00089 public:
00090     /** Create a new apa102 object
00091     * 
00092     *     
00093     * @param CKI clock pin
00094     * @param SDI data  pin
00095     * @param STRIP_LENGTH number of apa102 IC's i strip or array defaults to 32
00096     * @param reset_delay delay in us to allow latching data defaults to 800
00097     * @returns nothing   
00098     */
00099     apa102(PinName CKI, PinName SDI, int STRIP_LENGTH = 32, int reset_delay = 800);
00100     /** write RGB color data to strip or array
00101     * 
00102     * color data for each LED is 3 bytes int the order of rrggbb.
00103     * array must have STRIP_LENGTH number of elements
00104     *
00105     * @param strip_colors array of color data
00106     */
00107     void post(int *strip_colors);
00108     /** clears the array or strip (all off)
00109     */    
00110     void clear(void);
00111     /** set level of the entire array 0-100%
00112     * 
00113     * at low levels the colors may change because R,G or B
00114     * reaches 0.
00115     *
00116     * @param level level in percent
00117     * @returns current level
00118     */
00119     int level(int level=0);
00120     /** get/set reset/write delay
00121     * 
00122     * mainly for experimenting with reset values without recompiling,
00123     * leave at default to begin with & then lower to get faster execution.
00124     *
00125     * @param delay delay in us
00126     * @returns delay in us
00127     */    
00128     int delay(uint32_t reset_delay=100);
00129   
00130 private:  
00131     DigitalOut _CKI;
00132     DigitalOut _SDI;
00133     int _STRIP_LENGTH;
00134     int _level;
00135     int _reset_delay;
00136     inline void write_hi();
00137     inline void write_lo();
00138     inline void write_bit(bool bit);
00139     inline void write_word(uint32_t word, int bits = 32);
00140     inline void write_done();
00141     inline void preamble();
00142     inline void afterword();
00143 };
00144 
00145 #endif