LED matrix display - MD_Parola, MD_MAX72xx and MD_MAXPanel

My latest project is a scrolling text display.

Parola is a modular scrolling text display using MAX7219/21 LED matrix display controllers. The display is made up of any number of identical modules that are plugged together to create a wider/longer display.

The aim was to create a 'lego-like' approach to LED matrix display, using standard 8x8 LED matrices. The software supports this flexibility through a scalable approach that only requires the definition of the number of modules to adapt existing software to a new configuration.

The library implements functions to simplify the implementation of text special effects on the LED matrix.

  • Text left, right or center justification in the display
  • Text scrolling, appearance and disappearance effects
  • Control display parameters and animation speed
  • Support for hardware SPI interface

Hardware and software are available at GitHub - MajicDesigns/MD_Parola: Library for modular scrolling LED matrix text displays.
A video of the system working at Parola for Arduino - LED Matrix with MAX7219 controller - YouTube

1 Like


That looks tremendous - well done!

I had a few modules laying about that I picked up from DX but wouldn't you know it, they don't have the connectors on the edges so they don't chain anywhere as nicely as yours.

Great stuff. Of course I'll have Popcorn playing on tight rotation on brain-FM now for the rest of the afternoon after your video :slight_smile:

Cheers ! Geoff

Thanks. I started with the DX/eBay modules as well but they have the connector on the wrong edge so I designed my own.

Wow Marco,

what can I say "magnifico" What a great range of effects, I cannot think of anything else you might make them do but I am sure you will think of something. I had a look at your links but I must be missing something. Where can the control boards be purchased and where might there be information for connecting the switching controls and associated wiring,

thanks Pedro

Links for downloads lead here Pedro

Thanks Crossroads. I saw the library file on the original link but not the board files.

Sharp as a tack today Pedro 8)

This now makes any 7219 projects that I try pale into insignificance

Thanks Pedro. I am sure that it could do a lot more but I have run out of interest at the moment and want to move on to something else. Maybe if others write effects they can be built into a future release ...

Documentation is included with the library in the docs folder as an html file.

Boards are not 'for sale' as such, but it is easy enough to use the SeedStudio files to have some made. It is actually quite cheap (about AUS$15 delivered to Australia) for 10 boards, so if you have not tried doing this before, give it a go. Takes about 2 weeks from order to postman delivering.

Thanks Marco,

you are too humble. I did not realise that you could get boards made so cheaply, so I will definitely order some and "start to a soldering" I have been having a go at a bit of toner transfer PCB making at home, but having some professionally made boards to work with would be great. Keep up the good work,


If you check e-bay, there are plenty of MAX7219 modules that have a chip, matrix, and input & output pins.
For example:

SMD versions too

I did buy one of those larger units on eBay, as I started out wanting to use these 'off the shelf' type - they are pretty cheap. The problem (for me at least) is that the connections do not allow them to be joined up without cables. My design is similar but has connectors on the edges so the modules can be just plugged together.

The SMD units are more like where I would like to be at, but they are too expensive for my budget.

If one set of female headers is replaced with female right angle headers,
then adjacent boards can be plugged together.

If one set of female headers is replaced with female right angle headers,
then adjacent boards can be plugged together.

No doubt, but then with the joined units you have the matrix, the IC and then the next matrix. The matrices do not butt up against each other so, unless I am missing something, you can't build a continuous display (ie, matrix next to matrix next to matrix with no gaps).

Edit: for the sake of clarity I am not referring to the SMD units.

Very nice work. This is something I may look into using sometime.

Edit: for the sake of clarity I am not referring to the SMD units.

Where did you source your 8x8 matrices for use on your boards, and have you tried more than 10 connected?


The section of the video showing 'Scrolling' has 12 units daisy chained and working together. That's all the boards I have made up to date. At this stage I don't expect to be building up the remaining 8 spare PCB (I had 2 lots of 10 made up), but I can't see any issues arising from having more of the units connected. Any specific reason you see 10 as a limit?

I get my 8x8 matrices from eBay. The last lot I bought were from http://www.ebay.com.au/itm/230754163950?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649.

The controller chips come from Tayda Electronics http://www.taydaelectronics.com. They are about $1.25 each, so are probably not 'genuine' but seem to work perfectly well. Here is an interesting article about that http://tronixstuff.wordpress.com/2013/05/16/the-max7219-led-display-controller-real-or-fake/. I also get my passive components from Tayda.

Thanks !

Any specific reason you see 10 as a limit?

No reason, I actually mis-counted the modules in the video :slight_smile:


The web site has been updated with an additional PDF file documenting the hardware BoM, component sources, and assembly of the PCB.

Great job on the PDF Marco


I have just completed populating eight of your boards and would just like to compliment you on your well written assembly documentation
+1 Buddha points from me 8)


That's top feedback Pedro. It did look very comprehensive. I've ordered my components - going to tack 20 of these boards onto my next Seeed order :slight_smile: