Is it possible to control the motor speed without using a potentiometer?

Question

Arduino

I want to implement a program that will control the on / off and various changes through the interface. For example, when you press the "on laser" button, the laser turns on. There were no problems with this, but nothing happens with controlling the speed of rotation of the motor - there are no changes without a potentiometer, but it is undesirable for me to use it in the design of the device. Since my knowledge in arduino and all the physics that happens there is not deep enough for me, I may not be able to see the problems, so I ask for help from knowledgeable people.
Thank you in advance.

Answer 1

Is it possible to control the motor speed without using a potentiometer?

Depends on the type of motor. In the case of a brushed motor, pulse-width modulation can help. In the case of a brushless motor with direct access to the windings, you can try changing the switching speed of the windings.

Answer 2

Judging by the mention of the potentiometer, you are most interested in how you have to control the speed changes. So, you can't turn the knob, but you can use the buttons. In many music On the players, the volume is not controlled by a knob, but by a pair of buttons marked + and -. In the same way, you can arrange motor speed control, you just have to set the default initial speed when you turn on the device - zero, maximum, or something in between.
Well, how to arrange it programmatically - here your imagination should show itself. For a collector motor, the buttons must change the supply voltage or duty cycle of the PWM pulses, for a brushless synchronous or stepping motor, the switching frequency of the motor phases.

Answer 3

You need to google what is PWM and how to use it
and also study a series of articles
Then you will learn that you need to control the motor through a transistor . You
cannot control the motor through a potentiometer, because. most often the motor has more current than that for which the potentiometer is designed. And not for these purposes is the potentiometer.
To get started, take a weak bipolar transistor like SS8050 and a weak motor and try to control the shim.