PWM EC motor not running at full speed

Projects General Guidance
1

Hi Everyone,

I have a very basic setup to control an EC Motor. It takes PWM and I can control the speed, but it won't go full speed.

Here's my code:

int potPin = A0;    
int potValue = 0;  
int fan = 3;      

void setup() {
	Serial.begin(9600);
	pinMode(fan, OUTPUT);
}

void loop() {
	potValue = analogRead(potPin); 
	analogWrite(fan, potValue);  
	Serial.println("work ");     
	delay(10);                    
}

so super basic. The potentiometer I use is a standard 10k.
Anything wrong with my code?

2

Why not print out potValue that will probably show the problem.

3

that gives me nice 0-1023 readings.

I also tried reading the PWM value by adding

int potPin = A0;    
int potValue = 0;  
int fan = 3;      
byte PWM_PIN = 3;
 
int pwm_value;

void setup() {
	pinMode(fan, OUTPUT);
	pinMode(PWM_PIN, INPUT);
  Serial.begin(9600);
}

void loop() {
	potValue = analogRead(potPin); 
	analogWrite(fan, potValue);  
	//Serial.println("Programmed by 3Ddude");
	//Serial.print(potValue);
	delay(10);                    

  pwm_value = pulseIn(PWM_PIN, HIGH);
  Serial.println(pwm_value);
  delay(100);
}

but that gives me very weird readings, with 0 on both ends of the potentiometer

4

jojonl:
that gives me nice 0-1023 readings.
...

Doesn't PWM run from 0-255?

Just try writing 255 and see if it runs full speed.

5

potValue has range 0-1023, the 2nd parameter to analogWrite has range 0-255!

Also setting pin 3 as OUTPUT and then immediately to INPUT doesn't make much sense.

Steve

6

Always pays to read the reference manual;

void loop()
{
  val = analogRead(analogPin);   // read the input pin
  analogWrite(ledPin, val / 4);  // analogRead values go from 0 to 1023, analogWrite values from 0 to 255
}