Can Arduino Due generate mechanical vibration with specific frequency?

Dear all,

Hi. I'm trying to generate mechanical vibration with specific carrier and modulation frequency.

Some of my references stated, "vibrotactile stimulation based on a 175Hz sinusoidal carrier-wave modulated by a 27Hz wave."

I started from the simple blink code:

analogWrite(11, 255);
delay(25);
analogWrite(11, 0);
delay(25);

However, the vibration strength varied depending on delay, and I'm not sure if I went wrong.

According to the specification, its PWM frequency is 1000Hz, so I think it is possible to make the mechanical vibration, but my approach seems wrong.

I appreciate any comments and ideas.

Thank you!

P.S.,

I will attach vibration motors to PWM pins (+ for PWM pins and - for GND pins) to deliver the vibration, as others did

What sort of modulation are you thinking of - amplitude or frequency ?

The author of the reference added the plot.

I think it’s amplitude modulation.

signal.png

Amplitude and frequency of vibration motors are hard coupled, you cannot change them independently.

A PWM signal output from a DUE will swing from 0V to 3.3V (no negative value).

I assume you’re not connecting the motors directly to the Due. You need some sort of amplifier/driver.

The vibration motors I have found consist of a dc motor turning an offset mass - which has high inertia.
Because of the inertia you will not be able to change the rotational speed (ie frequency) very fast.

You can find a circuit diagram to drive it from pwm on my page here

However I dont think you will be able to generate the vibration signal you require with a simple vibration motor.

KyunghoWon:
analogWrite(11, 255);
delay(25);
analogWrite(11, 0);
delay(25);

Don't know for sure about the Due but on most Arduinos that's equivalent to:

digitalWrite(11, HIGH);
delay(25);
digitalWrite(11, LOW);
delay(25);
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