Diff: Adafruit_DotStar.h

Revision:

0:cbd607fc4caa

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Adafruit_DotStar.h	Wed Feb 03 11:39:23 2016 +0000
@@ -0,0 +1,199 @@
+#include "mbed.h"
+
+// Color-order flag for LED pixels (optional extra parameter to constructor):
+// Bits 0,1 = R index (0-2), bits 2,3 = G index, bits 4,5 = B index
+#define DOTSTAR_BGR (0 | (1 << 2) | (2 << 4))
+#define DOTSTAR_GBR (0 | (2 << 2) | (1 << 4))
+#define DOTSTAR_BRG (1 | (0 << 2) | (2 << 4))
+#define DOTSTAR_RBG (2 | (0 << 2) | (1 << 4))
+#define DOTSTAR_GRB (1 | (2 << 2) | (0 << 4))
+#define DOTSTAR_RGB (2 | (1 << 2) | (0 << 4))
+#define DOTSTAR_MONO 0 // Single-color strip WIP DO NOT USE YET
+SPI spi(p5,p6,p7);
+
+class Adafruit_DotStar
+{
+
+public:
+  
+    Adafruit_DotStar(uint16_t n, uint8_t o=DOTSTAR_RGB);
+    ~Adafruit_DotStar(void);
+    void
+    begin(void),                            // Prime pins/SPI for output
+          clear(),                                // Set all pixel data to zero
+          setBrightness(uint8_t),                 // Set global brightness 0-255
+          setPixelColor(uint16_t n, uint32_t c),
+          setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b),
+          show(void),                             // Issue color data to strip
+          updateLength(uint16_t n);               // Change length
+    uint32_t
+    Color(uint8_t r, uint8_t g, uint8_t b), // R,G,B to 32-bit color
+          getPixelColor(uint16_t n) const;        // Return 32-bit pixel color
+    uint16_t
+    numPixels(void);                        // Return number of pixels
+    uint8_t
+    getBrightness(void) const,              // Return global brightness
+                  *getPixels(void) const;                  // Return pixel data pointer
+
+private:
+
+    uint16_t
+    numLEDs;                                // Number of pixels
+    uint8_t
+    brightness,                             // Global brightness setting
+    *pixels,                                 // LED RGB values (3 bytes ea.)
+    rOffset,                                // Index of red in 3-byte pixel
+    gOffset,                                // Index of green byte
+    bOffset;                                // Index of blue byte
+
+    void
+    spi_init(void);
+};
+
+Adafruit_DotStar::Adafruit_DotStar(uint16_t n, uint8_t o):
+    brightness(0), pixels(NULL),
+    rOffset(o & 3), gOffset((o >> 2) & 3), bOffset((o >> 4) & 3)
+{
+    updateLength(n);
+}
+
+Adafruit_DotStar::~Adafruit_DotStar(void)   // Destructor
+{
+    if(pixels)                delete[] pixels;
+}
+
+void Adafruit_DotStar::begin(void)   // Initialize SPI
+{
+    spi_init();
+}
+
+void Adafruit_DotStar::updateLength(uint16_t n)
+{
+    if(pixels) delete[] pixels;
+    uint16_t bytes = (rOffset == gOffset) ?
+                     n + ((n + 3) / 4) : // MONO: 10 bits/pixel, round up to next byte
+                     n * 3;              // COLOR: 3 bytes/pixel
+    if(pixels = new uint8_t[bytes]) {
+        numLEDs = n;
+        clear();
+    } else {
+        numLEDs = 0;
+    }
+}
+
+// SPI STUFF ---------------------------------------------------------------
+void Adafruit_DotStar::spi_init(void)
+{
+    // Setup the spi for 8 bit data,
+    // second edge capture, with a 1MHz clock rate
+    spi.format(8, 0); // mode0 POL:positive PHA:ラッチ先行
+ //   spi.frequency(19000000);
+    spi.frequency(1000000);
+}
+
+void Adafruit_DotStar::show(void)
+{
+
+    if(!pixels) return;
+
+    uint8_t *ptr = pixels, i;            // -> LED data
+    uint16_t n   = numLEDs;              // Counter
+    uint16_t b16 = (uint16_t)brightness; // Type-convert for fixed-point math
+
+    for(i=0; i<4; i++) spi.write(0);    // Start-frame marker
+    if(brightness) {                     // Scale pixel brightness on output
+        do {                               // For each pixel...
+            spi.write(0xFF);                //  Pixel start
+            for(i=0; i<3; i++) spi.write((*ptr++ * b16) >> 8); // Scale, write
+        } while(--n);
+    } else {                             // Full brightness (no scaling)
+        do {                               // For each pixel...
+            spi.write(0xFF);    //  Pixel start
+            for(i=0; i<3; i++) spi.write(*ptr++); // R,G,B
+        } while(--n);
+    }
+    for(i=0; i<4; i++) spi.write(0xFF); // End-frame marker (see note above)
+
+}
+
+void Adafruit_DotStar::clear()   // Write 0s (off) to full pixel buffer
+{
+    memset(pixels, 0, (rOffset == gOffset) ?
+           numLEDs + ((numLEDs + 3) / 4) : // MONO: 10 bits/pixel
+           numLEDs * 3);                   // COLOR: 3 bytes/pixel
+}
+
+// Set pixel color, separate R,G,B values (0-255 ea.)
+void Adafruit_DotStar::setPixelColor(
+    uint16_t n, uint8_t r, uint8_t g, uint8_t b)
+{
+    if(n < numLEDs) {
+        uint8_t *p = &pixels[n * 3];
+        p[rOffset] = r;
+        p[gOffset] = g;
+        p[bOffset] = b;
+    }
+}
+
+// Set pixel color, 'packed' RGB value (0x000000 - 0xFFFFFF)
+void Adafruit_DotStar::setPixelColor(uint16_t n, uint32_t c)
+{
+    if(n < numLEDs) {
+        uint8_t *p = &pixels[n * 3];
+        p[rOffset] = (uint8_t)(c >> 16);
+        p[gOffset] = (uint8_t)(c >>  8);
+        p[bOffset] = (uint8_t)c;
+    }
+}
+
+// Convert separate R,G,B to packed value
+uint32_t Adafruit_DotStar::Color(uint8_t r, uint8_t g, uint8_t b)
+{
+    return ((uint32_t)r << 16) | ((uint32_t)g << 8) | b;
+}
+
+// Read color from previously-set pixel, returns packed RGB value.
+uint32_t Adafruit_DotStar::getPixelColor(uint16_t n) const
+{
+    if(n >= numLEDs) return 0;
+    uint8_t *p = &pixels[n * 3];
+    return ((uint32_t)p[rOffset] << 16) |
+           ((uint32_t)p[gOffset] <<  8) |
+           (uint32_t)p[bOffset];
+}
+
+uint16_t Adafruit_DotStar::numPixels(void)   // Ret. strip length
+{
+    return numLEDs;
+}
+
+// Set global strip brightness.  This does not have an immediate effect;
+// must be followed by a call to show().  Not a fan of this...for various
+// reasons I think it's better handled in one's sketch, but it's here for
+// parity with the NeoPixel library.  Good news is that brightness setting
+// in this library is 'non destructive' -- it's applied as color data is
+// being issued to the strip, not during setPixel(), and also means that
+// getPixelColor() returns the exact value originally stored.
+void Adafruit_DotStar::setBrightness(uint8_t b)
+{
+    // Stored brightness value is different than what's passed.  This
+    // optimizes the actual scaling math later, allowing a fast 8x8-bit
+    // multiply and taking the MSB.  'brightness' is a uint8_t, adding 1
+    // here may (intentionally) roll over...so 0 = max brightness (color
+    // values are interpreted literally; no scaling), 1 = min brightness
+    // (off), 255 = just below max brightness.
+    brightness = b + 1;
+}
+
+uint8_t Adafruit_DotStar::getBrightness(void) const
+{
+    return brightness - 1; // Reverse above operation
+}
+
+// Return pointer to the library's pixel data buffer.  Use carefully,
+// much opportunity for mayhem.  It's mostly for code that needs fast
+// transfers, e.g. SD card to LEDs.  Color data is in BGR order.
+uint8_t *Adafruit_DotStar::getPixels(void) const
+{
+    return pixels;
+}
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