Help with lights and sound (can it do that? Will it work if I do this?)

Hi there

I have a few questions I could use some help with if poss.

While I'm not new to electronics in general, most of my experiance has been as a solder monkey for many years and it never really went further than that. However, I've recently started a new hobby making replica props, and have found myself increasingly reaserching and learning as much as I can about electronics and circuit design (which has been great fun so far).

I'm now in the R&D phase of making a custom PCB (boy, didn't I just jump on the deep end lol) for a project using an Arduino pro mini as the brains of the setup, but I'm not totaly sure of it's capabilitys.

Can it handle sound as well as LEDs?

Is there a limit to how many max7219s can be daisy chained (I'm looking at about 5 in total working in two seperate groups).

The LEDs will be arranged in two rows (one longer than the other, hence the odd number of 7219s) and will have a different set of sequences to each other.

I'm also uncertain of the total number of LEDs needed, but it's around 265-280. The total number will be dictated by the LEDs 5mm diameter, and the space they will will eventually occupy. The parts are still in development, so I haven't got a difinitive measurement for calculating the total number of LEDs needed yet (frustratingly).

If the total number of LEDs needed are less the the total number of outputs available (but still enough to need all 5 chips), can the max7219s take odd/less LEDs per chip to balence thing out (if it's needed), or do I fill each one and have one chip with only a few LEDs attached? Or a combo of both?

Thanks :slight_smile:

You may find this very helpful: Arduino Playground - MAX72XXHardware

I'm also uncertain of the total number of LEDs needed, but it's around 265-280.

Is it single color or RGB LEDs?
Number of LED's , that board can handle mainly limited by available memory size (2K). Using one byte to keep brightness, it counts to 1500 LEDs (leaving 500 bytes for main program code), or 1500 / 3 = 500 RGB.
I'm not familiar with MAX7219, sorry can't help you on this. Why you choose it? There are many others, 74HC595 shift register, for example.
There is one of my project I did with this IC: