How to use the MAX7219 LED Dot Matrix with an Arduino
Using a LED Dot Matrix in your next project can be a way to incorporate some cool little animations.
By using these 8X8 matrix modules you can create your own.
Since these modules use the MAX7219 LED driver chip, we will be able to turn on and off the 64 LEDs of each modules, using only 3 pins on our Arduino.
In this tutorial we will connect 2 of them together to display different animations on each one.
As you can see, even if we are using 2 Modules, the number of pins needed, does not increase.
VCC and Ground are connected to the Arduino.
Pin 12 is connected to DIN, Pin 11 is connected to CLK and Pin 10 is connected to CS.
Our Sketch will make use of the “LedControl” Library to communicate with the MAX7219 modules.
Download and extract it to your Library folder, then restart your IDE software.
The code below assumes that we have 2 Dot Matrix connected together in cascade, but you can modify it easily if you have more or less of them connected.
We select the module we want to write to by using a number based on where it is in the chain, starting from 0 for the first one, 1 for the second, and so on…
As always you can have a look at the tutorial video for more information.
Copy and paste the above code in the Arduino IDE to program your Arduino.
Download the LedControl library created by Eberhard Fahle here: https://github.com/wayoda/LedControl/releases
Once downloaded, just extract the content of the zip files inside your “arduino/libraries” folder.