Diff: main.cpp

Revision:

0:35d68d1652e1

Child:

1:054df9ecd479

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Nov 05 16:50:38 2014 +0000
@@ -0,0 +1,152 @@
+#include "mbed.h"
+#include "wsDrive.h"
+
+// time period between each movement
+#define updatePeriodMS 25
+
+// number of LEDs in chain
+#define chainLen 144
+
+// length of the fade off behind the bright spot.
+// 1/8th of the chain length seems to look good (18 LEDs for a 144 chain)
+#define glowTail (chainLen/8)
+
+// background brightness left after the tail has passed.
+// final brightness = peak/backgroundRatio
+// set to be the same as the glow tail length for a smooth transition
+#define backgroundRatio glowTail
+
+// set the pulldown and then create the driver
+DigitalIn dummy(P0_21,PullDown);
+wsDrive ledDriver(P0_21,P0_22,P1_15);
+
+// mbuino stnadard definitions
+DigitalIn progMode(P0_3,PullDown); // fix the power wasted if we ever sleep.
+BusOut LEDs(LED1, LED2, LED3, LED4, LED5, LED6, LED7); // control the LEDs
+
+Timer updateRateTimer;
+
+// pixel storage buffer
+pixelInfo pixelData[chainLen];
+
+void blankBuffer(pixelInfo *Ptr)
+{
+    memset( (void *)Ptr, 0, chainLen*sizeof(pixelInfo) );
+}
+
+void setPixel (pixelInfo *pixel, pixelInfo *colour, float level)
+{
+
+    pixel->R = (unsigned char) (colour->R * level);
+    pixel->G = (unsigned char) (colour->G * level);
+    pixel->B = (unsigned char) (colour->B * level);
+}
+
+
+void setTrail (pixelInfo *colour, int peakPoint, bool increasing, int len)
+{
+    int pixelToUpdate = peakPoint;
+    for (int pixel = 0; pixel <= len; pixel++) {
+        if (pixel == len) {
+            setPixel((pixelData+pixelToUpdate), colour, 1.0/backgroundRatio);
+            break;
+        }
+        setPixel((pixelData+pixelToUpdate), colour, 1.0 - (float)pixel/(float)len);
+        increasing ? pixelToUpdate-- : pixelToUpdate++;
+        if (pixelToUpdate == chainLen) {
+            increasing = false;
+            pixelToUpdate = peakPoint - 1;
+            pixel = pixel*2;
+        }
+        if (pixelToUpdate == -1) {
+            increasing = true;
+            pixelToUpdate = peakPoint + 1;
+            pixel = pixel*2;
+        }
+    }
+}
+
+
+void setColour(pixelInfo *colour)
+{
+    static int cycleNumber = 0;
+
+    const int maxCycle = 40;
+    if (cycleNumber > maxCycle)
+        cycleNumber = 0;
+
+    switch (cycleNumber) {
+        case maxCycle:
+            cycleNumber = 0;
+        case 0:
+            colour->R = 0x80;
+            colour->G = 0x00;
+            colour->B = 0x00;
+            break;
+        case 10:
+            colour->R = 0x00;
+            colour->G = 0x70;
+            colour->B = 0x00;
+            break;
+        case 20:
+            colour->R = 0x00;
+            colour->G = 0x00;
+            colour->B = 0x80;
+            break;
+        case 30:
+            colour->R = 0x50;
+            colour->G = 0x40;
+            colour->B = 0x50;
+            break;
+        default:
+            break;
+    }
+    cycleNumber++;
+}
+
+
+int main ()
+{
+    LEDs = 0;
+    // intialise variables
+    int peakPoint = 0;
+    bool increasing = true;
+
+    pixelInfo colour;
+    setColour(&colour);
+
+    blankBuffer(pixelData);
+
+    // give the LED driver the buffer to use.
+    ledDriver.setData(pixelData, chainLen);
+
+    LEDs = 1;
+
+    setTrail (&colour, peakPoint, increasing, glowTail); // set the LED data
+
+    updateRateTimer.start();
+    while (true) {
+        ledDriver.sendData(); // send the LED data
+        LEDs = LEDs+1;
+
+        increasing ? peakPoint++ : peakPoint--; 
+        if (peakPoint == chainLen) {
+            increasing = false;
+            peakPoint = chainLen-2;
+        }
+        if (peakPoint == -1) {
+            setColour(&colour);
+            increasing = true;
+            peakPoint = 1;
+        }
+        
+        // update to the next trail ready for the next update.
+        setTrail (&colour, peakPoint, increasing, glowTail); // set the LED data
+
+        // wait for the next update time.
+        while (updateRateTimer.read_ms() < updatePeriodMS) {
+        }
+        updateRateTimer.reset();
+    }
+
+}
\ No newline at end of file