Tutorial re: RTC and LED Matrix

Can anyone direct me to where I can find a tutorial on getting data from a DS3231 RTC and scrolling it on an LED matrix? I have found a couple of good ones on getting the data from the RTC so that is not a big problem. I also found some code for scrolling some text on a matrix as well but the problem is that they are not commented very well and I am not sure what is really going on in the code. What I would like, if at all possible, is to find a step-by-step tutorial on scrolling text on 4 or 5 8x8 MAX7219 matrix modules. One that clearly explains what the code is doing and why. Then I may be able to combine the tutorial on the RTC with the tutorial on the matrix so I will be able to code my project.

Thanks for any help.


Can anyone direct me to where I can find a tutorial on getting data from a DS3231 RTC and scrolling it on an LED matrix?

Getting data from an RTC is clearly documented in many places. There are libraries for most of the common RTCs, including the DS3231.

"Scrolling" that data on an LED matrix depends on what you mean by "scrolling" and which LED matrix you have.

Post a link to the matrix you are using.

Thank you. As mentioned in my post, I have some good information on the RTC so that should not be a problem. What I am looking for is a good step-by-step tutorial on scrolling text on a LED matrix. I will be using a series of 4, or possibly 6, 8x8 matrix modules that use the MAX7219. I want to be able to take the data received from the RTC, time, date, etc. and scroll it on the matrix. I may also use a temperature & humidity module as well.

I have looked at a few pieces of code that people have used to scroll text across an LED matrix but they are not very well commented. There are a few matrix projects out there that supply code to do this but they want you to just copy the code and paste it in the project with no real explanation as to what the code is doing or why. So I am looking for a tutorial that will clearly explain how text is scrolled across an LED matrix, eg: what each line of code is doing.

The module is found here:


Have a look at the MD_Parola library (links below). One of the examples is a temp/time/humidity display on a LED matrix. You will also need the MD_MAX72xx library from the same place.

The module you have is called a GENERIC module in the MD_MAX72xx library. You will need to modify the MD_MAX72xx.h file to select this type of matrix. There is a lot of documentation about doing this with the library.

Thanks. I'll take a look at the example. Hopefully it will be well commented so that I can understand whats going on and I'll eventually be able to write my own code. :slight_smile: