Diff: main.cpp

Revision:

0:f38492690f0e

Child:

1:3b59b44884cd

diff -r 000000000000 -r f38492690f0e main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Mar 12 18:41:42 2014 +0000
@@ -0,0 +1,180 @@
+/*
+ * Adafruit NeoPixel 8x8 matrix example
+ *
+ * This program displays a couple simple patterns on an 8x8 NeoPixel matrix.
+ *
+ * 3 buttons are used for DigitalIns, 2 control the brightness up and down,
+ * and the third switches patterns
+ */
+
+#include "mbed.h"
+#include "NeoStrip.h"
+#include "gt.h"
+
+#define N 64
+#define PATTERNS 3
+
+int hueToRGB(float h);
+void pattern0();
+void pattern1();
+void pattern2();
+
+// array of function pointers to the various patterns
+void (*patterns[])(void) = {&pattern0, &pattern1, &pattern2};
+
+NeoStrip strip(p18, N);
+DigitalIn b1(p20); // brightness up
+DigitalIn b2(p19); // brightness down
+DigitalIn b3(p21); // next pattern
+
+// timer used for debugging
+Timer timer;
+
+int main()
+{
+	b1.mode(PullDown);
+	b2.mode(PullDown);
+	b3.mode(PullDown);
+	
+	int pattern = 0;
+	float bright = 0.2;	// 20% is plenty for indoor use
+	bool b3o = b3;		// old copy of button 3 to poll for changes
+
+	strip.setBrightness(bright);	// set default brightness
+	
+	while (true)
+	{
+		timer.reset(); // use a timer to measure loop execution time for debugging purposes
+		timer.start(); // for this application, the main loop takes approximately 3ms to run
+
+		// button 1 increases brightness
+		if (b1 && bright < 1)
+		{
+			bright += 0.01;
+			if (bright > 1)
+				bright = 1;
+			strip.setBrightness(bright);
+		}
+
+		// button 2 decreases brightness
+		if (b2 && bright > 0)
+		{
+			bright -= 0.01;
+			if (bright < 0)
+				bright = 0;
+			strip.setBrightness(bright);
+		}
+		
+		// button 3 changes the pattern, only do stuff when its state has changed
+		if (b3 != b3o)
+		{
+			if (b3 && ++pattern == PATTERNS)
+				pattern = 0;
+			b3o = b3;
+		}
+		
+		// run the pattern update function which sets the strip's pixels
+		patterns[pattern]();
+		strip.write();
+
+		timer.stop();
+		// print loop time if b3 is pressed
+		if (b3)
+			printf("Loop Time: %dus\n", timer.read_us());
+		
+		wait_ms(10);
+	}
+}
+
+// pattern0 displays a static image
+void pattern0()
+{
+	strip.setPixels(0, N, gt_img);
+}
+
+// display a shifting rainbow, all colors have maximum
+// saturation and value, with evenly spaced hue
+void pattern1()
+{
+	static float dh = 360.0 / N;
+	static float x = 0;
+
+	for (int i = 0; i < N; i++)
+		strip.setPixel(i, hueToRGB((dh * i) - x));
+	
+	x += 1;
+	if (x > 360)
+		x = 0;
+}
+
+// display a shifting gradient between red and blue
+void pattern2()
+{
+	// offset for each pixel to allow the pattern to move
+	static float x = 0;
+
+	float r, b, y;
+
+	for (int i = 0; i < N; i++)
+	{
+		// y is a scaled position between 0 (red) and 1.0 (blue)
+		y = 1.0 * i / (N - 1) + x;
+		if (y > 1)
+			y -= 1;
+
+		// if on the left half, red is decreasing and blue is increasng
+		if (y < 0.5)
+		{
+			b = 2 * y;
+			r = 1 - b;
+		}
+
+		// else red is increasing and blue is decreasing
+		else
+		{
+			r = 2 * (y - 0.5);
+			b = 1 - r;
+		}
+
+		// scale to integers and set the pixel
+		strip.setPixel(i, (uint8_t)(r * 255), 0, (uint8_t)(b * 200));
+	}
+
+	x += 0.003;
+	if (x > 1)
+		x = 0;
+}
+
+// Converts HSV to RGB with the given hue, assuming
+// maximum saturation and value
+int hueToRGB(float h)
+{
+	// lots of floating point magic from the internet and scratching my head
+	float r, g, b;
+	if (h > 360)
+		h -= 360;
+	if (h < 0)
+		h += 360;
+	int i = (int)(h / 60.0);
+	float f = (h / 60.0) - i;
+	float q = 1 - f;
+	
+	switch (i % 6)
+	{
+		case 0: r = 1; g = f; b = 0; break;
+		case 1: r = q; g = 1; b = 0; break;
+		case 2: r = 0; g = 1; b = f; break;
+		case 3: r = 0; g = q; b = 1; break;
+		case 4: r = f; g = 0; b = 1; break;
+		case 5: r = 1; g = 0; b = q; break;
+		default: r = 0; g = 0; b = 0; break;
+	}
+	
+	// scale to integers and return the packed value
+	uint8_t R = (uint8_t)(r * 255);
+	uint8_t G = (uint8_t)(g * 255);
+	uint8_t B = (uint8_t)(b * 255);
+
+	return (R << 16) | (G << 8) | B;
+}
+