New Product: MOD-LED8x8RGB stackable RGB LED MATRIX


MOD-LED8x8RGB is intelligent 8×8 RGB LED module, it allow many modules to be stacked together.


If we look at the back side there are two connectors named EXT-IN and EXT-OUT when two modules are stack together EXT-IN of the one snap to EXT-OUT of the other so both get connected.

MOD-LED8x8RGB works with 5V power supply as you can see on the two sides there are big copper pads named VCC/GND and VCC1/GND1 when modules are snap together permanently (if you make big screen) is good these VCC-VCC1 and GND-GND1 to be connected between the modules so better power distribution is achieved.


to connect MOD-LED8x8RGB you will need ARDUINO working with 5V like OLIMEXINO-32U4 – make sure the power jumper is set to 5V as OLIMEXINO-32U4 can work both on 3.3 and 5V.

Then you should connect OLIMEXINO-32U4 to MOD-LED8x8RGB as on above picture in this way:

  • D13 -> EXT-IN.LATCH
  • 5V -> EXT-IN.VCC

All next MOD-LED8x8RGB modules snap together, if you make new row of modules use jumper wires to connect EXT-OUT of the most right module on the first row to the EXT-IN of the most left module in the next row and etc.

Working with Arduino led8x8rgb.h library:

led8x8rgb.h and font.h are necessary to work with MOD-LED8x8RGB, you can download them from GitHub:

how to use it?

first define how many matrixes you have connected by altering bigX and bigY numbers in led8x8rgb.h

then you can use color variable to set your color from 0 – black to 7- white

there are two other variables cX and cY which define where on screen to print text or characters and these get automatically updated after printing to new position

the library have functions available:

  • drawPixel(x,y) draws drawPixel at X,Y coordinates (1,1) is upper left corner
  • drawLine(x1,y1,x2,y2) draws line
  • drawRectangle(x1,y1,x2,y2) draws rectangle
  • drawSolidRectangle(x1,y1,x2,y2) draws solid rectangle
  • drawElipse(x,y,rx,ry) draws elipse
  • drawCircle(x,y,r) draws circle
  • drawTriangle(x1,y1,x2,y2,x3,y3) draws triangle
  • drawChar(c) – draws char at cX, cY and updates cX, cY
  • drawString(s) – draws string at cX, cY and updates cX, cY
  • lScroll() – scrolls all screen left 1 column
  • rScroll() – scrolls all screen right 1 column
  • scrollCharLeft(c) – scrolls one character from the bottom right matrix to the left
  • scrollCharRight(c) – scrolls one character from the upper left matrix to the right
  • scrollString( s, dir) – scrolls string left or right depend on dir

Restless_Dancer.ino, Sentence.ino and Winking_Face.ino are demo codes made with led8x8rgb.h library.

Note that MOD-LED8x8RGB is not simple shift register matrix, but have microcontroller inside, so once you shift the info IN and LATCH it the microcontroller takes care to refresh the image on the matrix, this way with slow SPI you can drive large displays as no need to permanently shift new and new images to the screen as on the dummy RGB matrixes.

Here is video of the demo code from the GitHUb:

22 Comments (+add yours?)

  1. Richard Laniel
    Jun 21, 2013 @ 20:40:59


    How much does it costs? And when will it be available?

    Thank you.


  2. Ivan
    Jun 23, 2013 @ 08:02:42

    When do you plan to release the schematics? I am interested in what is the uC on that thing and how it is supposed to flashed if there is new firmware


  3. Ivan
    Jun 24, 2013 @ 21:11:04

    One more thing: Is it possible to control the brightness of that thing?


  4. Gonzalo
    Oct 08, 2013 @ 00:54:02

    Hi there, can I drive these display from a computer/raspberry pi? or do I need a Arduino in the middle to send commands and talk spi?



  5. Patrick Christensen
    Dec 03, 2013 @ 22:55:47

    What is the best way to turn on all the leds at the same time to say green?


  6. Matthew
    Mar 12, 2014 @ 08:27:22

    Can you describe how to update the firmware on the board?


  7. Jesús
    Sep 02, 2014 @ 23:47:36

    I want to know if yo can help me to make this system but using a mouse to read the pixels of an image and play it on the matrix?


  8. banupriya
    Jan 30, 2015 @ 12:27:55

    can v transfer data from arduino serial moniter to mod8*8 rgb led matrix


  9. Alexx
    Mar 30, 2015 @ 22:21:42

    How do you connect it to arduino and manage to use the font.h and lcd8x8rgb.h libraries? I`m trying for 2 weeeeeeeks. I posted even on your forum, but you send me here, and there`s no help here. It`s only about olimexino.

    I want to run a led matrix exactly like this, from you, but it has only red leds, on arduino. On what pin latch goes? What about sck? What about data? And the program?


    • OLIMEX Ltd
      Mar 31, 2015 @ 10:44:04

      Then you should connect OLIMEXINO-32U4 to MOD-LED8x8RGB as on above picture in this way:

      D13 -> EXT-IN.LATCH
      5V -> EXT-IN.VCC
      GND -> EXT-IN.GND

      you must run OLIMEXINO on 5V!


  10. billy
    Jun 02, 2015 @ 01:20:52

    can I buy only shield? i already have led matrix :/


  11. Tudor
    Oct 12, 2015 @ 10:55:05

    What’s the maximum current draw of the matrix?


  12. Daniel Fernandes
    Aug 25, 2017 @ 04:33:05

    Hello Friend! Where I can find: Restless_Dancer.ino, Sentence.ino and Winking_Face.ino

    Thank you


  13. SK
    Aug 25, 2017 @ 19:00:26

    Also, the product page lists more links under the software section:


  14. lrflow
    Oct 17, 2017 @ 20:23:27

    Is the Mod Led 8×8 plug and play or do you have to program. I am trying to make it work with arduino uno or will it only work with OLIMEXINO-32U4 and arduino Leonardo.


    • Daniel Fernandes
      Nov 17, 2017 @ 21:21:50

      Try switching from Tools> Board to Arduino Duemilanove but first take the Chip out of the board to write directly to OLIMEXINO;


  15. Daniel Fernandes
    Jul 17, 2018 @ 06:02:14

    I wonder if I can use the codes with Colorduino? And what would the connections of the Pins be like?


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: