Looking for Suggestions on Driving 600+ LEDs in Asymmetric Matrix

Thread Starter

PropForge

Joined Mar 5, 2016
14
I'm in the process of designing an mono-color LED matrix that is basically in the shape of a horseshoe/rainbow, with the ability to control individual LEDs, preferably with an Arduino, as I'm familiar with them. As of now, due to space constraints, I'm using 0603 LEDs, but that eliminates the ability to use addressable LEDs (smallest I've found is 2020). Essentially, I have 16 columns of different numbers of rows (The diagram below is just to illustrate the shape and doesn't reflect the exact number of LEDs per row).
LED_Layout_AAC.jpg
I've considered breaking them into groups of 8x8s to use MAX7219s, but with those, I'd need ~11 of them, which is not ideal. The TLC5940 also came to mind, but I lack experience with them. Something in my head is telling me to treat the columns 1-16 as digits and not worry too much about the row lengths.

Mostly what I'm looking for is suggestions for other ICs or design schemes that would set me off on an appropriate path, as I'm sure there plenty of ways to skin this cat.
 

Thread Starter

PropForge

Joined Mar 5, 2016
14
Right now, I'm going with the idea of having 16 columns with up to 63 rows, so I'd use 4 TLC5940s to sink the 63 LEDs in the rows, but I need an appropriate way to control the 16 columns. In order to multiplex the columns, would a pair of 595 shift registers with transistors be the appropriate approach?
 

dl324

Joined Mar 30, 2015
9,127
I'd wire them as a 16 by X matrix and just drive one LED at a time. Multiplexing will require driving the LEDs at a higher peak current, so the Arduino's 20mA sink/source capability won't be sufficient. You'd need one line driver/sink for each row and column.
 

dendad

Joined Feb 20, 2016
3,075
Have you looked at the addressable LEDs?
WS2811 or similar are available as individual LEDs...
WS2811_LEDs.png

or in strips...
WS2821_Strip.png

This will allow you to select individual colour and brightness.

For 600+ LEDs, multiple controllers will probably be needed, not just drivers, to get the update speed to usable times.
 

dendad

Joined Feb 20, 2016
3,075
Just a thought, if you are after small size, why not use an LCD or OLED display? Is there any particular reason you want to go with LEDs?
A display could be hidden behind a panel with holes drilled in it if you want that sort of look.
 
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