74HC595 - Shift register
Output up to 768 PWM signals from one Arduino. ShiftPWM | ElcoJacobs.com. Control many PWM outputs with only 3 Arduino pins ShiftPWM is a software PWM library for Arduino that uses shift registers to expand the number of PWM outputs.
With only 3 data pins, you can control an almost unlimited amount of PWM outputs. ShiftPWM support topic. Latest update: Support not using the SPI. Update August 9 2012:I finally had the time to completely rewrite the documentation.
You can now find schematics for normal RGB LED's, LED strips and high power LED's on www.elcojacobs.com/shiftpwm. I also updated the library to include load balancing and made the initialization much cleaner. ExtraCore running Shiftpwm. Multiple rgb leds with shift registers. Yes, I've made a thing using 96 RGB LEDs with 12 shiftregisters for the LEDs.
Actually I'm not finished programming the thing yet (TTT), but the display works :-) In my case it's organized as 6 matrices of 4 by 4 LEDs each, hence 2 shiftregisters per matrix. Using 4 bits as row multiplexers, which really is identical in all of them, so I could have saved some shiftregisters (two or three). ShiftOut. Learning Examples | Foundations | Hacking | Links Started by Carlyn Maw and Tom Igoe Nov, 06 Shifting Out & the 595 chip At sometime or another you may run out of pins on your Arduino board and need to extend it with shift registers.