Create LEDtest.ino

Adafruit_X2_Time_Ball/Arduino/LEDtest/LEDtest.ino

@@ -0,0 +1,35 @@
+/*****************************************************************************
+Sketch for testing WS2801 LED strands - lights one LED along length of strand.
+Because only one LED is lit at a time, can safely be powered from Arduino +5V.
+*****************************************************************************/
+
+#include "SPI.h"
+
+int nPixels = 150;
+
+void setup() {
+  SPI.begin();
+  SPI.setBitOrder(MSBFIRST);
+  SPI.setDataMode(SPI_MODE0);
+  SPI.setClockDivider(SPI_CLOCK_DIV16); // 1 MHz
+}
+
+int p = 0; // Current pixel being lit
+
+void loop() {
+  int  i, j;
+
+  // Issue data for all LEDs in strand regardless  
+  for (i=0; i < nPixels; i++) {
+    // Each LED = 3 bytes; white if current pixel, else off
+    for(j=0; j < 3; j++) {
+      SPI.transfer((i == p) ? 0xff : 0x00);
+    }
+  }
+
+  // LEDs automatically latch on pause
+  delay(25);
+
+  // Advance to next pixel, then back to start
+  if(++p >= nPixels) p = 0;
+}