LED matrices and MAX7219 ic’s

A 10 60mmx60mm Led matrices controlled by an ATmega328 + 10 MAX7219 ic’s from Bajdi Electronics:

Made a big LED matrix this week using 10 60mmx60mm LED matrices. I designed the PCB’s myself and had them made in China. Every PCB has a MAX7219 and a header to plug the LED matrix in. The 10 PCB’s are connected together using jumpers. Writing code for the MAX7219 is really easy thanks to the fantastic Parola Arduino library.

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7 Comments

  1. I really think that MAX7219s are far too expensive. For lower power applications, a sub-$1 attiny can do everything the Maxim part does and more, and for higher current you can always attach column driver FETs.

    1. It depends on how important the component’s provenance is. Right now, a “max7219” can be had for less than $2 delivered via ebay. This price is actually for a kit that includes an LED matrix, a PCB, socket, headers and other needed passives. If you don’t want all the extras, you can get a lot of 10 of just the driver ICs for less than $6 delivered.

      1. Any MAX7219 less than $5-6 is a fake!

        I use the AS1107 which is pin compatible and has a wider voltage range. Still cost about $5. But is a real part and not supporting chinese knock-offs.

        Here is my project I did last year.

    2. There is one very big difference between an LED driver like the MAX7219 and a generic microcontroller. Current limiting. Occasionally you might get lucky with a micro and the sink/source capabilities might be around what you need for driving arrays of LEDs, but by the word of the specs you can’t be sure every time – directly driving I mean. Having a settable constant current limit means things will be consistent.

      Of course, there are more options than the maxim chips that are probably cheaper and more efficient (TI has some rather nice LED drivers). However, when all you have is a hammer, all problems look like a nail.

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