To control vibration motor frequency with Arduino Due

Dear all,

Hello.

I want to use vibro-tactile stimulation for changing brain activities, but there are issues in controlling vibration motor frequency using PWM.

For example, researchers stated that they controlled stimulation frequency as 21~25Hz with 1Hz steps (resonant-like frequency) using PWM with Aruduino Due.

I don't really understand what they have done.

To my knowledge, vibration motor has their own RPM, and it can be converted to Hz by RPM/60.

Can I control vibration motor frequency specifically by merely control PWM value?

Thank you Best regards, Kyungho Won

Its a motor, like any other, drive it with a motor driver and PWM.

Can I control vibration motor frequency specifically by merely control PWM value?

Yes, because PWM controls the average voltage as seen by the motor. Since speed is proportional to applied voltage in a dc motor, the frequency of vibration is controlled by the voltage applied. PWM output is a fixed frequency, only the duty cycle changes. The higher the PWM value, the higher the output voltage and the higher the frequency of vibration due the eccentric in the motor.

Most vibration motors only need an appropriate logic level mosfet to control them since it is a simple, unidirectional application.