Can Arduino Due generate mechanical vibration with specific frequency?

Projects General Guidance
1

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

2

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

3

The author of the reference added the plot.

I think it's amplitude modulation.

signal.png

4

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

5

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

6

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

7

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.

8

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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