Thursday, August 1, 2013

AVR Atmega multiple 8x8 led matrix using MAX7219

This library implements a 8x8 led matrix for AVR Atmega.



It uses just one MAX7219 serial input/output common-cathode display drivers and 3 ports.
MAX7219 can refresh leds leving more resources to microcontroller.
This library uses MAX7219 without the need of SPI. User can setup scan limit and intensity setup.
Multiple led matrix can be attached.


With simple functions, it gives your the ability to:
  • power on / off a single led
  • setup a selected row
  • setup an 8x8 matrix
Setup parameters are stored in file ledmatrix7219d88.h


Code

Notes
  • read risk disclaimer
  • excuse my bad english
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Location: Milano, Italia

25 comments:

  1. UnknownMarch 1, 2015 at 6:01 PM

    Great job , it works. Can you help me how to define function


    ledmatrix7219d88_setcol

    it will set upright diodes in colums.

    eg. 0b11111111 will light up 1st column ?

    i tried to display moving text in 2 led displays.

    Thanks!

    ReplyDelete
    Replies
    1. Davide GironiMarch 1, 2015 at 7:21 PM

      Hello, it's a few that i do not look at this library, anyway, you can simply use the ledmatrix7219d88_setled function, but if you are trying to reduce the number of operation involved, i think you have to tweek around the max7219 library to.

      Delete
  2. UnknownOctober 28, 2016 at 5:13 PM

    Which program did you use for your schematics file? I can't open it and the image makes no sense compared to other images online. I tried to run the code at it's not working the same as in the video. My wiring must be different since I do not have the matrix + chip module for the led display.

    ReplyDelete
    Replies
    1. Davide GironiOctober 30, 2016 at 11:31 AM

      Hello, it's EagleCAD.

      Delete
    2. UnknownNovember 1, 2016 at 2:49 PM

      Thanks! I'm just having a hard time getting it to work. Everything should be wired properly but all it does is turn all LEDs on then off instead of a fancy loop.

      Delete
    3. Davide GironiNovember 1, 2016 at 5:19 PM

      Hello, you can check it with a scope, or a logic analizer, what's going on over the bus. Then you will understand why this is not going. Or you can use uart as a debug output interface, sending to your terminal register status, or any kind of debug messages that may help you.

      Delete
  3. UnknownNovember 23, 2016 at 3:48 PM

    This is not working.I checked this through the Proteus simulator as in the schematic and programmed it in the Winavr programmers notepad.But nothing works.And tried it on Atmega32 and Atmega8 both.Can you please help me regarding this.
    In the program it has called the interrupt header but haven't called a interrupt in the program.
    Are the pins connected in the schematic are correct?

    ReplyDelete
    Replies
    1. Davide GironiNovember 23, 2016 at 11:46 PM

      Hello, this works for me as you can see for ATmega8 on presold MAX7219 matrix led board. I've also test it on clean MAX7219 and leds. Unluckly i do not use Proteus. You can check your micro to MAX7219 bus using a logic analizer, to assure that the output is working.

      Delete
  4. KushanDecember 13, 2016 at 1:10 AM

    i cant make a hex file,can u send me hex,to kushan.walakulu@gmail.com

    ReplyDelete
  5. UnknownDecember 24, 2016 at 6:09 PM

    for the max7219 is it possible use it only with i2c?

    ReplyDelete
    Replies
    1. Davide GironiDecember 26, 2016 at 9:11 PM

      Hello, no, but by datasheet the MAX7221, which is similar to the MAX7219 is compatible with SPI, QSPI, and MICROWIRE.

      Delete
  6. JohnOctober 4, 2017 at 1:36 AM

    can i use this to hack carpark systems and show text message on the parking autopay machine

    ReplyDelete
    Replies
    1. Davide GironiOctober 4, 2017 at 9:22 PM

      Hello, this is simply a library to drive 8x8 matrix led. You can use to show text message, yes.

      Delete
  7. MuneebNovember 3, 2017 at 4:47 PM

    Hello, I'm facing some authentication problem while downloading the library from sourceforge.Could you share it on github or google drive please.

    ReplyDelete
    Replies
    1. Davide GironiNovember 4, 2017 at 11:04 AM

      Hello, you can find it there: https://expirebox.com/download/9902e68901d7968cf2c36cd5a521fe6a.html Link expires in 2 days

      Delete
    2. MuneebNovember 5, 2017 at 9:19 AM

      Thanks a lot!

      Delete
  8. ihsanSeptember 21, 2018 at 6:01 AM

    moving text, can u send me source c & hex,to ihsanwidodo44@gmail.com
    dot matrix p10 panel, code vision, atmega16.

    ReplyDelete
  9. UnknownOctober 29, 2018 at 11:37 AM

    I used the library with Atmega32 along with one LED breakout board,
    The led blinking works for only two cloumns rest of the 6 columns wont blink, but it takes the time required to blink other 6 columns then repeats blinking the two columns. can you give me any hint why is it so?

    ReplyDelete
  10. vishvaJanuary 19, 2020 at 9:54 PM

    Can you send me the hex file. vishvajayasanka@gmail.com

    ReplyDelete
  11. Festo-sanFebruary 9, 2023 at 9:58 PM

    Hey, how do i do the pin out for the atmega328p? and, does it work for the microcontroller?

    ReplyDelete
    Replies
    1. Davide GironiFebruary 10, 2023 at 8:08 AM

      Hello, yes it works, indeed I've also use this code on ATm2ga328. It will be easy the porting. Just look at the code and made appropriate changes, but it's something you have to do, I can not do this for you.

      Delete

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