16 channel PWM LED driver based on the Texas Instruments TLC5940 chip.
http://www.pjrc.com/teensy/td_libs_Tlc5940.html
http://code.google.com/p/tlc5940arduino/
http://playground.arduino.cc/Learning/TLC5940
https://github.com/PaulStoffregen/Tlc5940
The TLC5940 chip SCK pin is sensitive to signal overshoot. When used with Teensy 4.0 or other high speed hardware, especially if using long wires, you may need to add a resistor inline with the SCLK signal.
https://forum.pjrc.com/threads/71009?p=323766&viewfull=1#post323766