LedControl library

Projects General Guidance
1

Hello Arduino forum,

Have started working a project with the Maxim7219 chip.

It is quite frustrating that in the Arduino Libraries list

there is a link marked
"-LedControl - for controlling LED matrices or seven-segment displays with a MAX7221 or MAX7219."
But no where on that page is there a link to the actual LedControl library.
The article dives into " API-functions ... called through a variable of type LedControl"
but no where as far as I can see is there a link to the LedControl library or the LedControl.h file.

A copy of an LedControl.h was found at

So it was figured this file could be copied and put in the Arduino libraries folder
in a folder called LedControl and all would be well.

This LedControl.h file begins

/*
LedControl.h - Event-Based Library for Arduino.
Copyright (c) 2011, Renato A. Ferreira
All rights reserved.

But then a file called LedControl.zip was found (Where its was found is not exactly sure because
I have searched so far and wide that I can't remember where I found it.) This zip file
has an examples subfolder with three PDE files, a keywords.txt file and a LesControl.cpp file

The LedControl.h file in the zip file begins
/*

  • LedControl.h - A library for controling Leds with a MAX7219/MAX7221
  • Copyright (c) 2007 Eberhard Fahle

So the LedControl.h file dated 2011 would seem to be more current but the LedControl.h
dated 2007 seems to be more complete.

Which file should be used?
Will it work to simply deploy whichever of the two files is correct to
a folder called "LedControl" in the Arduino "libraries" folder?

Thanks.

Allen Pitts, Dallas Texas

2

Hi Allen, It's hiding in plain sight on GitHub :slight_smile:

---------------------( COPY )---------------------
LedControl

LedControl is an Arduino library for MAX7219 and MAX7221 Led display drivers.
The code also works with the Teensy (3.1)

Documentation

Documentation for the library is on the Github Project Pages

Download

The lastest binary version of the Library is always available from the
LedControl Release Page

Install

The library can be installed using the standard Arduino library install procedure
-----------------( END COPY )----------------------

There's an example here, from a new book I helped edit:

http://arduino-info.wikispaces.com/_13_1_CountdownLED_Display

3

AllenPitts:
It is quite frustrating that in the Arduino Libraries list
http://www.arduino.cc/en/Reference/Libraries
there is a link marked
"-LedControl - for controlling LED matrices or seven-segment displays with a MAX7221 or MAX7219."
But no where on that page is there a link to the actual LedControl library.

Apologies if I am missing something here, but...

If you click on this link (from the Libraries page you referred to above)

LedControl - for controlling LED matrices or seven-segment displays with a MAX7221 or MAX7219.

You arrive at - Arduino Playground - HomePage which looks to be a very well documented library.

Near the bottom of that page there is a heading titled "Source code and Download" which has a link to GitHub - wayoda/LedControl: An Arduino library for MAX7219 and MAX7221 Led display drivers

Download the zip file - middle of page on the right hand side - install as per the provided instructions and you should be right to go.

Disclaimer - I have never used this library but it appears to be very well documented.

It looks like there may be two libraries which just happen to have the same name - you can't mix and match the .h or .cpp files from each version.

4

Hello Terry, Magic and the Arduino forum,

Is my face red. I read the
http://playground.arduino.cc/Main/LedControl
page four times and did not see the link to the GitHub
at the bottom.
Thanks.

Terry I saw the ArduinoInfo page. Lot of good stuff
there especially on library installation.
Thanks again

Allen in Dallas

PS. Stick around guys. I am starting a project that uses the Maxim7219
not as a seven segment or matrix but in a linear display . Hopefully
it will go smoothly but I may need some adult supervision.