I am looking to build a 3x3 RGB LED matrix with individually addressable LEDs as a form of user interface.
I do already have a micro controller available but want to use it only as high level controller, i.e. to either have it trigger a pre-stored lighting routine or sending a low-volume bit string that contains the information regarding the routine. A routine will run until the mc sends a new command, a sort of fire-and-forget setup.
By routine I mean for example one lit up led "running" in circles, or certain leds blinking with a certain frequency. Ideally fading animations would be possible -> high frequency of led value changes.
So now I am wondering what kind of ICs may already exist that would aid me in this endeavor. I have seen circuits using shift registers and the like, but not only do they use a lot of GPIOs, they also require the mc to constantly change GPIO outputs in order to produce animations.
I would like to delegate this to a dedicated chip and before I go building my own I would like to see what is already available.
So, if anyone has experience with this beyond what a simple google search would return (tried that😉), I would be grateful!