Pulse Width Modulation (PWM) Shield for Arduino
The PWM Shield will allow you to generate up to 16 PWM signals from your Arduino by utilizing the power of the Texas instrument TLC5940 16-channel PWM chip.
Use this board to increase the number of PWM pins available to your microcontroller for applications such as monocolor, multicolor or full-color LED displays, LED signboards, display backlighting, servo control, or any other project where a large number of PWM drivers are necessary.
In order to make this board suitable for use with servos, 2.2k pull-up resistors have been included on each output as well. Finally, the 2.2k resistor on the Iref pin sets the output current to 17.8mA but a parallel through-hole connection is provided for an additional resistor to increase the current if necessary. To determine the resistor value you need for a given output check the equations provided on the schematic below.