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MAX7219 replacement for common anode 7 segment displays? — Parallax Forums

MAX7219 replacement for common anode 7 segment displays?

CuriousOneCuriousOne Posts: 931
edited 2014-04-02 05:11 in General Discussion
Hello. Is there a replacement for MAX7219, without adding extra functionality or details, which can drive 7 segment common anode displays? It should provide multiplexing and decode mode, just as MAX7219 does and have SPI interface. Sure, there are MAX6954 and some others, but they add unnecessary complexity and absence of sample code.

Comments

  • TonyDTonyD Posts: 210
    edited 2013-11-08 04:36
    I've not seen a direct replacement for the MAX7219, I wish there was $12 for one is ridiculously expensive.
  • KC_RobKC_Rob Posts: 465
    edited 2013-11-09 19:35
    CuriousOne wrote: »
    Hello. Is there a replacement for MAX7219, without adding extra functionality or details, which can drive 7 segment common anode displays? It should provide multiplexing and decode mode, just as MAX7219 does and have SPI interface. Sure, there are MAX6954 and some others, but they add unnecessary complexity and absence of sample code.
    Take a look at Austria Micro Systems - if I recall correctly their AS1100 is a drop-in replacement.
  • CuriousOneCuriousOne Posts: 931
    edited 2013-11-10 06:10
    Yes, that's a great chip, but as datasheet says, it is also for common-cathode displays :(
  • KC_RobKC_Rob Posts: 465
    edited 2013-11-10 13:50
    CuriousOne wrote: »
    Yes, that's a great chip, but as datasheet says, it is also for common-cathode displays :(
    Sorry, my bad. I thought you were simply looking for a (more affordable) replacement. I should have read more closely. Oh well, perhaps my suggestion will help TonyD out. :)
  • TonyDTonyD Posts: 210
    edited 2013-11-11 05:58
    Spurred on by the ridiculously price of the MAX7219 I researched some more over the weekend and found the AS1107 from AMS, but it looks as if KC_Rob beat me to it.

    Sorry CuriousOne it won't drive CC LED display
  • PublisonPublison Posts: 12,366
    edited 2013-11-12 16:05
    I had the same dilemma a few months ago and purchased a few ICM7228 chips, as I was tied to Common Anode displays also. Not serial, and also a high price of $9.48, and a higher price of 10 pins.
  • PublisonPublison Posts: 12,366
    edited 2013-11-12 16:08
    TonyD wrote: »
    Spurred on by the ridiculously price of the MAX7219 I researched some more over the weekend and found the AS1107 from AMS, but it looks as if KC_Rob beat me to it.

    Sorry CuriousOne it won't drive CC LED display

    Did you mean to say that it will not drive Common Anode?
  • CuriousOneCuriousOne Posts: 931
    edited 2013-11-12 20:56
    I've researched subject a bit further and come to some ideas:

    As a partial solution, usable in some cases, ICM7217 from Maxim is also not a bad chip.
    If agree to BCD input, bunch of NTE8374 or HEF4543B can be used, too.
  • cholzcholz Posts: 1
    edited 2014-04-02 05:11
    I have written a program in c for the PIC16F819 which replicates most of the functionality of the MAX7219 including cascading, decode mode, test mode, and scan limit. Unfortunately the 819 micro doesn't have enough IO to include the decimal point and it can only drive 4 digits but it would be fairly easy to modify the code to run on a larger micro that could support it as well as more than 4 digits. Also you have to be careful not to send data to the micro too rapidly or you risk missing things. The absolute max clock rate for data in is about 250 kHz. The nice thing is the 819 or other suitable micro is dirt cheap. I can share the code if you're interested.
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