Test program for my Multi_WS2811 library that started out as a fork of heroic/WS2811. My library uses hardware DMA on the FRDM-KL25Z to drive up to 16 strings of WS2811 or WS2812 LEDs in parallel.
Dependencies: Multi_WS2811 mbed MMA8451Q
Fork of WS2811 by
NOTE: I have accidentally pushed changes for another fork of this program that I used in the recent Georgetown Carnival Power Tool Races. When I get some time, I will restore the test program to its original glory.
You can see my power tool racer (Nevermore's Revenge) here

This tests my FRDM-KL25Z multi-string WS2811/WS2812 library. It uses the accelerometer to change the rainbow phase on two strings of LEDs as well as the touch sense to change brightness.
A video of this program in operation is here.
Here is the library that I developed to run the LEDs:
Import libraryMulti_WS2811
Library allowing up to 16 strings of 60 WS2811 or WS2812 LEDs to be driven from a single FRDM-KL25Z board. Uses hardware DMA to do a full 800 KHz rate without much CPU burden.
Diff: WS2812.cpp
- Revision:
- 15:331e139672b5
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/WS2812.cpp Thu Dec 05 15:12:47 2013 +0000
@@ -0,0 +1,82 @@
+// 800 KHz WS2812 driver, kinda.
+//
+// Parameterized and modified to use soft SPI.
+// Jas Strong <jasmine@electronpusher.org>
+// Modified to use hard SPI by Ned Konz <ned@bike-nomad.com>
+/*****************************************************************************/
+
+#include "LedStrip.h"
+#include "WS2812.h"
+
+WS2812::WS2812(int n, PinName mosi, PinName sclk) :
+ LedStrip(n),
+ spi(mosi, NC, sclk)
+{
+#ifdef TARGET_KL25Z
+ spi.format(8, 3);
+#else
+ spi.format(16, 3);
+#endif
+ spi.frequency(800e3 * 16); // 12.8 MHz => 800KHz bit rate
+}
+
+/*
+ * These chips use a one-wire protocol based on a sort of NRZ signalling- jas.
+ */
+
+inline void WS2812::writebit(bool bit)
+{
+ if (bit) {
+#ifdef TARGET_KL25Z
+ spi.write(0xff); // 8 high
+ spi.write(0x00); // 8 low
+#else
+ spi.write(0xff00);
+#endif
+ } else {
+#ifdef TARGET_KL25Z
+ spi.write(0xe0); // 3 high, 5 low
+ spi.write(0x00); // +8 low
+#else
+ spi.write(0xe000);
+#endif
+ }
+}
+
+void WS2812::write(uint8_t byte)
+{
+ writebit(byte & 0x80);
+ writebit(byte & 0x40);
+ writebit(byte & 0x20);
+ writebit(byte & 0x10);
+ writebit(byte & 0x08);
+ writebit(byte & 0x04);
+ writebit(byte & 0x02);
+ writebit(byte & 0x01);
+}
+
+void WS2812::begin(void)
+{
+ blank();
+ show();
+}
+
+void WS2812::blank(void)
+{
+ memset(pixels, 0x00, numPixelBytes());
+}
+
+void WS2812::show(void)
+{
+ uint16_t i, nl3 = numPixelBytes(); // 3 bytes per LED
+ while (guardtime.read_us() < 50)
+ /* spin */;
+ __disable_irq();
+ for (i=0; i<nl3; i++ ) {
+ write(pixels[i]);
+ }
+ __enable_irq();
+ guardtime.reset();
+}
+
+
Ned Konz


Generic WS2811/WS2812