Diff: NeoStrip.cpp

Revision:

0:9f237b11f0a8

Child:

1:f531a2be180d

diff -r 000000000000 -r 9f237b11f0a8 NeoStrip.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NeoStrip.cpp	Wed Mar 12 18:36:58 2014 +0000
@@ -0,0 +1,93 @@
+/**********************************************
+ * NeoStrip.cpp
+ *
+ * Allen Wild
+ * March 2014
+ *
+ * Controls a strip of Adafruit NeoPixels, addressable RGB LEDs
+ * Currently, because of the global nature of the IO register and bitmask variables,
+ * it is only possible to use one NeoStrip instance at a time.
+ *
+ * This library supports only the NXP LPC1768!
+ */
+
+#include "mbed.h"
+#include "NeoStrip.h"
+
+// function to write to the strip, implemented in ARM assembly
+extern "C" void neo_out(NeoColor*, int);
+
+// FastIO register address and bitmask for the GPIO pin
+// because these are imported in the assembly
+uint32_t neo_fio_reg;
+uint32_t neo_bitmask;
+
+NeoStrip::NeoStrip(PinName pin, int N) : N(N)
+{
+	bright = 0.5;
+	Nbytes = N * 3;
+	strip = (NeoColor*)malloc(N * sizeof(NeoColor));
+	if (strip == NULL)
+	{
+		printf("NeoStrip: ERROR unable to malloc strip data");
+		N = 0;
+	}
+	
+	gpio_init(&gpio, pin, PIN_OUTPUT);		// initialize GPIO registers
+	neo_fio_reg = (uint32_t)gpio.reg_dir;	// set registers and bitmask for
+	neo_bitmask = 1 << ((int)pin & 0x1F);	// the assembly to use
+}
+
+void NeoStrip::setBrightness(float bright)
+{
+	this->bright = bright;
+}
+
+void NeoStrip::setPixel(int p, int color)
+{
+	int red = (color & 0xFF0000) >> 16;
+	int green = (color & 0x00FF00) >> 8;
+	int blue = (color & 0x0000FF);
+	setPixel(p, red, green, blue);
+}
+
+void NeoStrip::setPixel(int p, uint8_t red, uint8_t green, uint8_t blue)
+{
+	// set the given pixel's RGB values
+	// the array is indexed modulo N to avoid overflow
+	strip[p % N].red = (uint8_t)(red * bright);
+	strip[p % N].green = (uint8_t)(green * bright);
+	strip[p % N].blue = (uint8_t)(blue * bright);
+}
+
+void NeoStrip::setPixels(int p, int n, const int *colors)
+{
+	int r, g, b;
+	for (int i = 0; i < n; i++)
+	{
+		r = (colors[i] & 0xFF0000) >> 16;
+		g = (colors[i] & 0x00FF00) >>8;
+		b = colors[i] & 0x0000FF;
+		setPixel(p+i, r, g, b);
+	}
+}
+
+void NeoStrip::clear()
+{
+	for (int i = 0; i < N; i++)
+	{
+		strip[i].red = 0;
+		strip[i].green = 0;
+		strip[i].blue = 0;
+	}
+}
+
+void NeoStrip::write()
+{
+	__disable_irq();		// disable interrupts
+	neo_out(strip, Nbytes);	// output to the strip
+	__enable_irq();			// enable interrupts
+	wait_us(50);			// wait 50us for the reset pulse
+}
+
+