What I'm looking to make is a multiplexed 16x16 LED grid with with 2-bits of brightness (aka 4 levels of brightness). There might be a better way to do this.
I've built a prototype 8x8 grid with an Arduino Nano, it works great. I have 8 pins to connect the anodes and 8 pins to the cathodes. I'm using 3v 20ma 5mm LEDs
But, since arduino only has 6 PWM pins, i can't get the resolution I want. I'm looking to get more pwm pins
I'm looking at the ADAFRUIT 24-CHANNEL 12-BIT PWM LED DRIVER, which gives 24 pins of PWM over SPI. While 8x8 I can do on the board, if I wanted to do a 16x16 matrix while connected to the Arduino. Is it possible to use pins from the LED driver to run the anodes (16 of the 24 pins) with PWM while using 16 GPIO pins on the arduino to run the cathodes (to get more pins for multiplexing)? From my experiments, only the anode needs PWM while the cathode just needs to be high or low for multiplexing. Would the VCC for the Driver need to come from a power supply?