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Topic: Cascade two MAX7219s (Read 1 time) previous topic - next topic

RichKC24

Have one MAX7219 running an 8x8 martrix using MD_MAX72XX library.  Working great.

Now trying to cascade 2 MAX7219 chips.

Searched forum and datasheet and now I think they are wired together properly.

Question 1.  Do I need to change anything in lib.h,  or .h or .ino files to turn on cascading in addition to #define MAX_DEVICES.

Question 2:  Is there some bare bones code I can run to test my setup?  There are many examples in MD_MAX72xx but they are complex.  Would just like to turn on a row of LEDs across both matrices as a test and to learn how to control the MAX7219.

thank you

artisticforge

Have one MAX7219 running an 8x8 martrix using MD_MAX72XX library.  Working great.

Now trying to cascade 2 MAX7219 chips.

Searched forum and datasheet and now I think they are wired together properly.

Question 1.  Do I need to change anything in lib.h,  or .h or .ino files to turn on cascading in addition to #define MAX_DEVICES.

Question 2:  Is there some bare bones code I can run to test my setup?  There are many examples in MD_MAX72xx but they are complex.  Would just like to turn on a row of LEDs across both matrices as a test and to learn how to control the MAX7219.

thank you
seek and ye shall find.

duckduckgo.com search for "arduino sketches for max7219"

http://tronixstuff.com/2013/10/11/tutorial-arduino-max7219-led-display-driver-ic/
http://playground.arduino.cc/Main/LEDMatrix
http://www.instructables.com/id/Arduino-LED-Matrix-Clock/



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RichKC24

Tried them.  Is there anything I need to set in the .h, lib.h or .ino files to turn on cascade to second MAX7219?

artisticforge

Tried them.  Is there anything I need to set in the .h, lib.h or .ino files to turn on cascade to second MAX7219?

I do not have these items. How am i suppose to know if you need to change something?
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larryd

#4
Dec 28, 2017, 07:59 pm Last Edit: Dec 28, 2017, 08:00 pm by larryd

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RichKC24

Thanks Larry.  Had a wiring error.

artisticforge

Tried them.  Is there anything I need to set in the .h, lib.h or .ino files to turn on cascade to second MAX7219?

You, obviously did not try them for if you had you would have found the wiring error.
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marco_c

For completeness:
Quote
Question 1.  Do I need to change anything in lib.h,  or .h or .ino files to turn on cascading in addition to #define MAX_DEVICES.
Nothing else. Once you have changed the library header file for your LED atrix type, the number of matrices are set at run time.

Quote
Question 2:  Is there some bare bones code I can run to test my setup?  There are many examples in MD_MAX72xx but they are complex.  Would just like to turn on a row of LEDs across both matrices as a test and to learn how to control the MAX7219.
The hardware testing example with MD_MAX72xx library is a simple example if you ignore all the text to help the user figure out what is happening.
Arduino Libraries https://github.com/MajicDesigns?tab=Repositories
Parola for Arduino https://github.com/MajicDesigns/Parola
Arduino++ blog https://arduinoplusplus.wordpress.com

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