Smart Seriel RGB LED

[Macgman2000]

Hello,

I am looking for a library or sample code for controlling a string of serial RGB LEDS. I would appreciate the help!

It uses a type of manchester code per bit. WS2812 sold on Adafruit.

Thanks!
Nick

[Anobium]

Hi Nick and welcome,

This is essentially an SPI device. This means you send a stream of three bytes to control the color and a small wait to allow the chip to process the bytes.

There is a lot of example code on the internet and converting to Great Cow BASIC is not a challenge.

What level of coder are you?
Which microcontroller are you planning to use?
Is the only device you plan to connect to the microcontroller ?
And, have you seen some code or a Youtube video that shows what the end goal should be?

Anobium

[Macgman2000]

Hi Anobium,

Thanks for the response. I am just starting out on the Arduino Uno. Basically I want to vary the colors in a loop going through different fades and mixes. Nothing really in mind other than learning how to do it. Any code reference for SPI I should look at?

Thanks!
Nick

[Anobium]

Your code needs to look something like this. This is not tested - so, your task is to decompose and make it work. :-)

Lookup in the Help SPIMODE and SPITransfer, also,
Look at the demos for a demo program called \GreatCowBasic\Demos\SPI Digital Pot Solutions\MCP4xxx SPI Pot\MCP4141_HardwareSPI_SimpleDemo_mega328p@16.gcb this has the same chip and working code for an SPI solution.

Do not hestitate to ask questions.

I hope this get you started.

Anobium

PS. When you get it going... I want the program back to publish as an demo!!

:-)

~~~~~

'''A program for GCGB and GCB.
'''
'''@author
'''@licence GPL
'''@version
'''@date
'''**************

; ----- Configuration
#chip mega328p, 16
#include <uno_mega328p.h></uno_mega328p.h>

; ----- Constants
' Four ports are required for HW SPI but we are only use two - data out and clock lines
' #define WS2812_CS DIGITAL_10
#define WS2812_SCK DIGITAL_13
#define WS2812_DO DIGITAL_11
' #define WS2812_DI DIGITAL_12

' Define Colors
#define WS2812_BLACK   0x000000
#define WS2812_RED     0xFF0000
#define WS2812_GREEN   0x00FF00
#define WS2812_BLUE    0x0000FF
#define WS2812_WHITE   0xFFFFFF

; ----- Define Hardware settings
' None
; ----- Variables
dim loopx as word

'We use the lower three bytes to hold the color
dim WS2812color as long

; ------ Start of main Program

'Required to initialise the device
WS2812Init

; ----- Example code

    do Forever

        WS2812WriteLEDs ( WS2812_RED , 1 )
        wait 500 ms

        WS2812WriteLEDs ( WS2812_GREEN , 1 )
        wait 500 ms

        WS2812WriteLEDs ( WS2812_WHITE , 1 )
        wait 500 ms

    Loop

Sub WS2812Init
SPIMode MasterFast, 0

  ' Four ports are required for HW SPI but we are only use two - data out and clock lines

' Dir WS2812_DI in
Dir WS2812_DO Out
Dir WS2812_SCK Out
' Dir WS2812_CS out

  ' Initial state of ports required for SW SPI
  set WS2812_DO off
  set WS2812_SCK off

End Sub

Sub WS2812WriteLEDs ( in LEDValue as long, in NumberofLEDs )

  'Send start frame
  SPITransfer ( 0x00, temp )
  SPITransfer ( 0x00, temp )
  SPITransfer ( 0x00, temp )
  SPITransfer ( 0x00, temp )


  for loopx = 0 to (NumberofLEDs+NumberofLEDs+NumberofLEDs) step 3

      'Maximum global brightness
      SPITransfer( 0xff, temp )
      SPITransfer( LEDValue, temp )                 'lower byte
      SPITransfer( LEDValue_H, temp )               'next byte
      SPITransfer( LEDValue_U, temp )               'last byte

  Next


  'End Frame
  loopx = 0
  do while loopx < NumberofLEDs

      'Send 8 more clock cycles
      SPITransfer( 0xff, temp )
      loopx = loopx + 16

  loop

End Sub

[Macgman2000]

Thanks for the starter code :) I will post back when I get things sorted.

Nick

[Anobium]

THIS POSTING/CODE HAS BEEN SUPERCEDED. PLEASE LOOK AT THE DEMONSTRATIONS FOR WORKING CODE.