Arduino•21h ago

Cant control speed of dc motor with potentiometer

I am trying to control the speed of my dc motor with my potentiometer. But when I turn the potentiometer to max it works but when I turn it a little bit the dc motor turn off. Any idea why?

14 Replies

MaderDash•21h ago

@Sloth do you mean. No microcontroller. Just the pot?

AnonEngineering•21h ago

100 years ago they controlled motors that way 😉

SlothOP•21h ago

Just pot wired to the hw 130 motor shield v1. And the shield is ona aurdiono uno.

MaderDash•21h ago

@Sloth so is the pot conected to the arduino. And your reading it by code?@Sloth

SlothOP•21h ago

Yes the middle pin is connected to A0 and 2 outside 5v and gnd

MaderDash•20h ago

Ok so. Make a serial print in code. And print out the value the pot is creating. @Sloth let me know what you get when turning the pot

SlothOP•20h ago

I did and the pot value is from 1023 to 0 but when I used the potvalue to set motor speed: this is code to set motor speed "motor.setspeed(potvalue)"

MaderDash•20h ago

Did it go smoothly? It went with a full sweep of the pot?

SlothOP•19h ago

In the graphic if i turned it to max it was not the smoothest but also not very static so in-between. And when it reached max it would be a flat line. Is this wat you mean?

MaderDash•16h ago

Yes. Ok now share your code

SlothOP•8h ago

#include <AFMotor.h> AF_DCMotor motor(1); int potpin = A0; int potval = 0; void setup() { Serial.begin(9600); // set up Serial library at 9600 bps Serial.println("Motor test!"); // turn on motor motor.setSpeed(0);
motor.run(RELEASE); } void loop() {
potval= analogRead(potpin);
Serial.print(potval); Serial.print("\n"); motor.run(FORWARD); motor.setSpeed((potval/1023)*255);

delay(100); } Here you go

AnonEngineering•1h ago

try this

c++
/*
  Arduino | coding-help
  Sloth 9/8/25 — 2:34 AM
*/

int potpin = A0;

void setup() {
  Serial.begin(9600);
  Serial.println("Get pot value test!\n");
}

void loop() {
  int potval = analogRead(potpin);
  int setSpeed = (potval / 1023) * 255;
  int mappedSpeed = map(potval, 0, 1023, 0, 255);
  Serial.print("potval: ");
  Serial.println(potval);
  Serial.print("setSpeed: ");
  Serial.println(setSpeed);
  Serial.print("mappedSpeed: ");
  Serial.println(mappedSpeed);
  Serial.print("\n");
  delay(1000);
}

c++
/*
  Arduino | coding-help
  Sloth 9/8/25 — 2:34 AM
*/

int potpin = A0;

void setup() {
  Serial.begin(9600);
  Serial.println("Get pot value test!\n");
}

void loop() {
  int potval = analogRead(potpin);
  int setSpeed = (potval / 1023) * 255;
  int mappedSpeed = map(potval, 0, 1023, 0, 255);
  Serial.print("potval: ");
  Serial.println(potval);
  Serial.print("setSpeed: ");
  Serial.println(setSpeed);
  Serial.print("mappedSpeed: ");
  Serial.println(mappedSpeed);
  Serial.print("\n");
  delay(1000);
}

nis•1h ago

I see what you did there

SlothOP•1h ago

Thx cant try yet but I'll get back to you when I tried it!

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Cant control speed of dc motor with potentiometer

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