Using the PWM Driver with Other Microcontrollers
Provide high-current open-drain MOSFET drivers for pulse width modulation (PWM)
on Microchip PIC, Arduio, Raspberry Pi, or other microcontrollers
In addition to using the PWM Driver Wildcard in conjunction with the PDQ Board, you can connect it to the digital outputs of other microcontrollers, such as Microchip Technology's popular PIC microcontrollers, the Arduino boards, or the Raspberry Pi, to enhance the current capability of their digital outputs. You can connect to static digital outputs for greater current drive, and you can connect to dynamic, pulse width modulated outputs too.
The inputs on header H6 of the PWM Wildcard require only logic level, 0-5 V or 0-3.3 V signals.
The board requires no controller side power for operation, although if you want the current sense outputs to work you must provide 5V power to the Current Sense Header, H3. You can then drive the board with logic-level PIC PWM signals from PIC microcontrollers, or from Arduino digital outputs, or from Raspberry Pi GPIO outputs by connecting the outputs to pins on H6. Make other connections to the Wildcard as described in its User Manual.
The outputs of the PWM Driver Wildcard are low-side current drivers capable of sinking up to 5A each. You an use them to control motors, lights, LEDs, fans, blowers, heaters, electromagnets, and other devices from you PIC microcontroller or Arduino based single board computer.
PWM is often used in motor control for efficiency. If you drive motors using PWM, be sure to use a PWM frequency above the audible range. Generally, motor windings will sing strongly if driven with PWM signals below about 5 KHz. Above that frequency the motor inductance reduces the ripple current and the mechanical stiffness of the windings prevents their shaking so much. If you drive the motor at 15 KHz or above there will be no audible noise.
PWM is also widely used in LED and light dimmer applications. If you drive the lamps at below 50 Hz flicker may be quite noticeable, so it's a good idea to use frequencies above 100 Hz.