main.cpp

00001 /*
00002  * Adafruit NeoPixel 8x8 matrix example
00003  *
00004  * This program displays a couple simple patterns on an 8x8 NeoPixel matrix.
00005  *
00006  * 3 buttons are used for DigitalIns, 2 control the brightness up and down,
00007  * and the third switches patterns
00008  */
00009 
00010 #include "mbed.h"
00011 #include "NeoStrip.h"
00012 #include "gt.h"
00013 
00014 #define N 64
00015 #define PATTERNS 3
00016 
00017 Serial pc(USBTX, USBRX);
00018 int hueToRGB(float h);
00019 void pattern0();
00020 void pattern1();
00021 void pattern2();
00022 
00023 // array of function pointers to the various patterns
00024 void (*patterns[])(void) = {&pattern0, &pattern1, &pattern2};
00025 
00026 NeoStrip strip(p21, N);
00027 int selekt=0;
00028 /*DigitalIn b1(p20); // brightness up
00029 DigitalIn b2(p19); // brightness down
00030 DigitalIn b3(p21); // next pattern*/
00031 
00032 // timer used for debugging
00033 Timer timer;
00034 
00035 int main()
00036 {
00037     pc.baud(115200);
00038     printf("Test af LED\r\n");      
00039     
00040     int pattern = 0;
00041     float bright = 0.2; // 20% is plenty for indoor use
00042     int b3o = selekt;       // old copy of button 3 to poll for changes
00043 
00044     strip.setBrightness(bright);    // set default brightness
00045     
00046     while (true)
00047     {
00048         timer.reset(); // use a timer to measure loop execution time for debugging purposes
00049         timer.start(); // for this application, the main loop takes approximately 3ms to run
00050 
00051         // button 1 increases brightness
00052         if ((selekt==1) && bright < 1)
00053         {
00054             bright += 0.01;
00055             if (bright > 1)
00056                 bright = 1;
00057             strip.setBrightness(bright);
00058         }
00059 
00060         // button 2 decreases brightness
00061         if ((selekt==2) && bright > 0)
00062         {
00063             bright -= 0.01;
00064             if (bright < 0)
00065                 bright = 0;
00066             strip.setBrightness(bright);
00067         }
00068         
00069         // button 3 changes the pattern, only do stuff when its state has changed
00070         if ((selekt==3) != b3o)
00071         {
00072             if (++pattern == PATTERNS) pattern = 0;
00073 
00074         }
00075         selekt=0;
00076         // run the pattern update function which sets the strip's pixels
00077         patterns[pattern]();
00078         strip.write();
00079 
00080         timer.stop();
00081         // print loop time if b3 is pressed
00082         if (pc.readable()) {
00083             switch(pc.getc()) {
00084             case '1': selekt=1; break;  
00085             case '2': selekt=2; break;  
00086             case '3': selekt=3; break;  
00087            }    
00088         }       
00089         wait_ms(10);
00090     }
00091 }
00092 
00093 // pattern0 displays a static image
00094 void pattern0()
00095 {
00096     strip.setPixels(0, N, gt_img);
00097 }
00098 
00099 // display a shifting rainbow, all colors have maximum
00100 // saturation and value, with evenly spaced hue
00101 void pattern1()
00102 {
00103     static float dh = 360.0 / N;
00104     static float x = 0;
00105 
00106     for (int i = 0; i < N; i++)
00107         strip.setPixel(i, hueToRGB((dh * i) - x));
00108     
00109     x += 1;
00110     if (x > 360)
00111         x = 0;
00112 }
00113 
00114 // display a shifting gradient between red and blue
00115 void pattern2()
00116 {
00117     // offset for each pixel to allow the pattern to move
00118     static float x = 0;
00119 
00120     float r, b, y;
00121 
00122     for (int i = 0; i < N; i++)
00123     {
00124         // y is a scaled position between 0 (red) and 1.0 (blue)
00125         y = 1.0 * i / (N - 1) + x;
00126         if (y > 1)
00127             y -= 1;
00128 
00129         // if on the left half, red is decreasing and blue is increasng
00130         if (y < 0.5)
00131         {
00132             b = 2 * y;
00133             r = 1 - b;
00134         }
00135 
00136         // else red is increasing and blue is decreasing
00137         else
00138         {
00139             r = 2 * (y - 0.5);
00140             b = 1 - r;
00141         }
00142 
00143         // scale to integers and set the pixel
00144         strip.setPixel(i, (uint8_t)(r * 255), 0, (uint8_t)(b * 200));
00145     }
00146 
00147     x += 0.003;
00148     if (x > 1)
00149         x = 0;
00150 }
00151 
00152 // Converts HSV to RGB with the given hue, assuming
00153 // maximum saturation and value
00154 int hueToRGB(float h)
00155 {
00156     // lots of floating point magic from the internet and scratching my head
00157     float r, g, b;
00158     if (h > 360)
00159         h -= 360;
00160     if (h < 0)
00161         h += 360;
00162     int i = (int)(h / 60.0);
00163     float f = (h / 60.0) - i;
00164     float q = 1 - f;
00165     
00166     switch (i % 6)
00167     {
00168         case 0: r = 1; g = f; b = 0; break;
00169         case 1: r = q; g = 1; b = 0; break;
00170         case 2: r = 0; g = 1; b = f; break;
00171         case 3: r = 0; g = q; b = 1; break;
00172         case 4: r = f; g = 0; b = 1; break;
00173         case 5: r = 1; g = 0; b = q; break;
00174         default: r = 0; g = 0; b = 0; break;
00175     }
00176     
00177     // scale to integers and return the packed value
00178     uint8_t R = (uint8_t)(r * 255);
00179     uint8_t G = (uint8_t)(g * 255);
00180     uint8_t B = (uint8_t)(b * 255);
00181 
00182     return (R << 16) | (G << 8) | B;
00183 }
00184