I need help building and programing a 23 x 23 rgb led matrix controlled with an Arduino Uno. The led display will be somewhat complex. I would prefer to discuss details of the project through private chat. I am willing to pay for services rendered.
23x23 matrix = 46 outputs, times 3 for the colours makes 138 outputs. And I guess you'll want to be able to adjust intensities, so make that 138 PWM outputs.
An Uno has 6 PWM pins.
"somewhat complex" I think is an understatement, unless you left out essential details.
IIRC you can also see the Matrix as 23 x 69 leds ==> 92 outputs. that saves 1/3 ... but still ...
It definitely can be done - but probably not with an Arduino. That's by just looking at those huge LED advertisting displays on top of and in front of buildings, to be seen from the other side of the harbour. Those things are three storeys tall, and some 50 meters wide. No idea how many LEDs go in there, other than that it's a lot, and they are RGB.
Some dedicated controller hardware will be needed.
For all things blinky and shiny, I suggest searching Adafruit.com for "RGB matrix". You can learn a lot about what is available off the shelf. The larger LED grids are designed to be driven by a Raspberry Pi.
Adafruit sells several neopixel matrixes. They are almost certainly designed to be tileable.
If you want to roll-your-own big RGB display with some high-power LEDs, they also sell the neopixel controller chips. 529 of them, and 1587 MOSFETs and you are good to go. Or there's something like this 3W module for $15 per.
The point is, the WS2811 is built to be daisy-chained and so only one output pin is required. And there's an arduino library.
Is it still active?