Ned Konz / Mbed 2 deprecated Multi_WS2811_test

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 Heroic Robotics

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

/media/uploads/bikeNomad/img_0482.jpg

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.

Last commit 13 Jun 2015 by Ned Konz

Files at this revision

API Documentation at this revision

Revision 13:1f65330abe92, committed 2013-07-23

Comitter:
heroic
Date:
Tue Jul 23 22:32:14 2013 +0000
Parent:
12:7ebd51549c04
Child:
14:c97261a9a282
Commit message:
Rework timing for constant execution time; do direct bitband writes for improved speed; change interrupt handling (turns out we can't have interrupts during an entire strip push, not just between bits).; ; Now works!

Changed in this revision

WS2811.cpp Show annotated file Show diff for this revision Revisions of this file
WS2811.h Show annotated file Show diff for this revision Revisions of this file 
--- a/WS2811.cpp	Thu Apr 11 22:16:07 2013 +0000
+++ b/WS2811.cpp	Tue Jul 23 22:32:14 2013 +0000
@@ -27,6 +27,14 @@
     printf("ws2811:  1000 iters took %d usec.\n", i);
     bogocal = (1000 / (onewire_speed_multiplier * i * 4.2)); // iterations per bitcell (417 nsec)
     printf("ws2811:  calibrating to %d bogojiffies.\n", bogocal);
+    
+    data_mask = dat.get_mask();
+    clock_mask = clk.get_mask();
+    data_set = dat.get_set();
+    data_clr = dat.get_clr();
+    clock_set = clk.get_set();
+    clock_clr = clk.get_clr();
+    
 }
 
 /*
@@ -34,7 +42,7 @@
  */
  
 void WS2811::write(uint8_t byte) {
-    __disable_irq();
+    
     for (int i=0; i<8; i++) {
         if (byte & 0x80)
             writebit(1);
@@ -42,26 +50,26 @@
             writebit(0);
         byte <<= 1;
     }
-    __enable_irq();
 }
 
 inline void WS2811::celldelay(void) {
-    for (int i = 0; i<bogocal; i++)
+    for (volatile int i = 0; i<bogocal; i++)
         /* do nothing */ ;
 }
 
-void WS2811::writebit(bool bit) {
+inline void WS2811::writebit(bool bit) {
     // first cell is always 1
-    dat = 1;
+    (*data_set) = data_mask;
     celldelay();
     if (bit) {
+        (*clock_set) = data_mask; // dummy, we don't care but must take constant time
         celldelay();
     } else {
-        dat=0;
+        (*data_clr) = data_mask;
         celldelay();
     }
     // last cell is always 0
-    dat=0;
+    (*data_clr) = data_mask;
     celldelay();
 }
 
@@ -82,10 +90,11 @@
     uint16_t i, nl3 = numLEDs * 3; // 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();
 }
 

--- a/WS2811.h	Thu Apr 11 22:16:07 2013 +0000
+++ b/WS2811.h	Tue Jul 23 22:32:14 2013 +0000
@@ -37,6 +37,12 @@
  private:
   DigitalOut dat;
   DigitalOut clk;
+  __IO uint32_t *data_set;
+  __IO uint32_t *clock_set;
+  __IO uint32_t *data_clr;
+  __IO uint32_t *clock_clr;
+  uint32_t clock_mask;
+  uint32_t data_mask;
   void write(uint8_t byte);
   void writebit(bool bit);
   void celldelay(void);