• NeoPixel (WS2812B) Demo

    In a previous thread (http://www.picbasic.co.uk/forum/showthread.php?t=18431) I've posted an example how to use those addressable RGB leds (WS2812B) aka NeoPixel. I've optimized the code and made a set of include files.

    The NeoPixels can be used with almost any PIC running at 20MHz. The only limit is the available RAM: you need 3 arrays, one for each colour (RGB). The size of each array is the number of leds to control. With a large number of pixels I suggest using a PIC18F. See PicBASIC manual for more information on arrays limits.

    A PIC running @20MHz is more than enough to make almost any animation. The values are pre-computed and then streamed in one shot. You have plenty of time to compute the next sequence unless you want to build a video screen!

    Two gamma correction files are supplied for better fades in or out. One is for PIC18F and one for the others.
    Ref.: https://learn.adafruit.com/led-trick.../the-quick-fix
    See NeoPixelDump.pbp for instructions.

    The demo code show you how to run them on PIC12F683. Now the only limit is your imagination! Be creative!

    http://youtu.be/QDAwFmu4YuM

    Demo code:
    Code:
    '****************************************************************
    '*  Name    : NeoPixelDemo.pbp                                  *
    '*  Author  : Michel Jasmin                                     *
    '*  Notice  : NO Copyright (c) 2014 Michel Jasmin  ;)           *
    '*          : No Rights Reserved                                *
    '*  Date    : 2014-11-29                                        *
    '*  Version : 1.0                                               *
    '*  Notes   : Demo how to use WS2812B (neoPixels) on            *
    '*          : a PIC12F683 @20MHz                                *
    '****************************************************************
    
    #IF __PROCESSOR__ = "12F683"
        #CONFIG
            __config _HS_OSC & _WDT_OFF & _MCLRE_ON & _CP_OFF
        #ENDCONFIG
    
    #ELSE
        #MSG "Wrong Processor selected!"
    #ENDIF
    
    DEFINE OSC 20
    DEFINE NO_CLRWDT 1  ' Don't waste cycles clearing WDT
    
    '------------ Const -------------------------
    
    NEO_NUM     CON 18  'Number of pixels
    
    '------------ Variables -------------------------
    
    NeoGreen    VAR BYTE[NEO_NUM]
    NeoBlue     VAR BYTE[NEO_NUM]
    NeoRed      VAR BYTE[NEO_NUM]
    NeoPixel    VAR BYTE            'Looping variable
    NeoPixValue VAR BYTE            'Value to be bit-banged
    
    '------------ ALIAS -------------------------
    
    NeoPin      VAR GPIO.2
    
    '-----------  Initialization -------------------------------
    
    Clear   ' Clear RAM before entry
    
    ANSEL = 0
    CMCON0 = 7  'Comparator disabled
    CCP1CON = 0
    WPU = 0
    TRISIO.2 = 0 'NeoPin
    
    NeoPin = 0
    
    GOSUB NeoInit
    
    '-----------  Main program -------------------------
    
    Main:
    
        GOSUB NeoPixelDump
        GOSUB NeoPixelRotate
    
        PAUSE 50
    
        GOTO Main
    
    END
    
    NeoInit:
        'Init values for 18 leds string.
        FOR NeoPixel = 0 TO (NEO_NUM - 1)
    
            IF NeoPixel < 3 THEN
                NeoGreen[NeoPixel] = 0
                NeoBlue[NeoPixel] = 0
                NeoRed[NeoPixel] = 64
    
            ELSEIF NeoPixel < 6 THEN
                NeoGreen[NeoPixel] = 0
                NeoBlue[NeoPixel] = 64
                NeoRed[NeoPixel] = 0
    
            ELSEIF NeoPixel < 9 THEN
                NeoGreen[NeoPixel] = 0
                NeoBlue[NeoPixel] = 64
                NeoRed[NeoPixel] = 64
    
            ELSEIF NeoPixel < 12 THEN
                NeoGreen[NeoPixel] = 64
                NeoBlue[NeoPixel] = 0
                NeoRed[NeoPixel] = 0
    
            ELSEIF NeoPixel < 15 THEN
                NeoGreen[NeoPixel] = 64
                NeoBlue[NeoPixel] = 0
                NeoRed[NeoPixel] = 64
            ELSE
                NeoGreen[NeoPixel] = 64
                NeoBlue[NeoPixel] = 64
                NeoRed[NeoPixel] = 0
            ENDIF
    
        NEXT
    
        RETURN
    
    NeoPixelRotate:
        FOR NeoPixel = 0 TO (NEO_NUM - 1)
            NeoGreen[NeoPixel] = NeoGreen[NeoPixel + 1]
            NeoBlue[NeoPixel] = NeoBlue[NeoPixel + 1]
            NeoRed[NeoPixel] = NeoRed[NeoPixel + 1]
        NEXT
    
        NeoGreen[NEO_NUM - 1] = NeoGreen[0]
        NeoBlue[NEO_NUM - 1] = NeoBlue[0]
        NeoRed[NEO_NUM - 1] = NeoRed[0]
    
        RETURN
    
    
    INCLUDE "..\_Include\NeoPixelDump.pbp"
    
    Attachment 8832Attachment 8832
    This article was originally published in forum thread: NeoPixel (WS2812B) Demo started by MichelJasmin View original post