Diff: main.cpp

Revision:

1:ca76237d2965

Parent:

0:60499ad28ea9

--- a/main.cpp	Fri Jul 25 15:22:59 2014 +0000
+++ b/main.cpp	Fri Aug 01 22:43:26 2014 +0000
@@ -1,28 +1,30 @@
 #include "mbed.h"
-#include "neopixel-spi.h"
+#include "neopixel.h"
 
-// A backing store for the pixel data.
-static size_t const count = 16;
-neopixel::Pixel pixels[count];
+// This must be an SPI MOSI pin.
+#define DATA_PIN p5
 
-// The pixel array control class.
-neopixel::Array array(p30);
-
-uint8_t IntensityForIndex(size_t index) {
-  uint32_t c = index % 512;
-  return (c >= 256) ? (256 - c) : c;
+void generate(neopixel::Pixel * out, uint32_t index, uintptr_t extra)
+{
+    uint32_t brightness = (index + extra) >> 3;
+    out->red   = ((index + extra) & 0x1) ? brightness : 0;
+    out->green = ((index + extra) & 0x2) ? brightness : 0;
+    out->blue  = ((index + extra) & 0x4) ? brightness : 0;
 }
 
-int main() {
-  size_t offset = 0;
-  while (1) {
-    for (size_t i = 0; i < count; i++) {
-      pixels[i].red   = IntensityForIndex((i * 10) + offset);
-      pixels[i].green = IntensityForIndex((i * 20) + offset);
-      pixels[i].blue  = IntensityForIndex((i * 40) + offset);
+int main()
+{
+    // Create a temporary DigitalIn so we can configure the pull-down resistor.
+    // (The mbed API doesn't provide any other way to do this.)
+    // An alternative is to connect an external pull-down resistor.
+    DigitalIn(DATA_PIN, PullDown);
+
+    // The pixel array control class.
+    neopixel::PixelArray array(DATA_PIN);
+
+    uint32_t offset = 0;
+    while (1) {
+        array.update(generate, 100, offset++);
+        wait_ms(250);
     }
-    array.Update(pixels, count);
-    wait_ms(10);
-    offset++;
-  }
 }