@Jeremy_Spencer I have one of those. Took me hours to find it.
I do typically use code to check my matrices, but keep in mind that some of them may be bad out of the box. I also bought those 2 devices to check them without needing a microcontroller:
https://www.amazon.com/gp/product/B01C89E61E and https://www.amazon.com/gp/product/B01DC0JKGY
You don’t need both, either will do, and I just bought both to try the different patterns they could do by default.
@Jaja1 did you get it working??
@Jeremy_Spencer no, i bought two pieces from aliexpress and both stopped working. i gave up and moved on to a simpler led matrix for my project using max7219 ic. it isn’t rgb tho. i’ll try to get my hands on a neopixel led strip next time.
thanks for the responses guys, i’ll get back to you when i get my hands on some neopixels.
@Jaja1 if you want to do your own matrix row scanning, see my library:
http://marc.merlins.org/perso/arduino/post_2015-01-06_Driver-for-direct-driving-single-to-3-color-LED-Matrices-with-software-PWM.html
otherwise this matrix works fine: https://www.amazon.com/gp/product/B07417BRFN