problem with big stepper motor speed control

Other Hardware Motors, Mechanics, Power and CNC
9

MarkT:
Well you clearly have a servomotor, not a stepper motor!

Anyway the issue is that its using the same step/direction interface as a stepper motor would,
which needs a high rate of pulses for a high speed. You are calling analogRead() which takes a
long time on ATmega microcontrollers - 110µs or so, limiting the pulse rate.

Your management of time is poor too - using delayMicroseconds() instead of micros(), so that
the code execution time eats into your performance.

Perhaps try replacing

void loop() {

customDelayMapped = speedUp(); // Gets custom delay values from the custom speedUp function
 // Makes pules with custom delay, depending on the Potentiometer, from which the speed of the motor depends
 digitalWrite(stepPin, HIGH);
 delayMicroseconds(customDelayMapped);
 digitalWrite(stepPin, LOW);
 delayMicroseconds(customDelayMapped);
}



by

void loop() {
 static unsigned long last_read= 0 ;
 if (millis() - last_read >= 20)   // only read pot occasionally
 {
   last_read += 20 ;
   customDelayMapped = speedUp(); // Gets custom delay values from the custom speedUp function
 }

// Makes pules with custom delay, depending on the Potentiometer, from which the speed of the motor depends
 static unsigned long last_step = 0 ;
 if (micros() - last_step >= customDelayMapped)
 {
   last_step += customDelayMapped ;  // schedule next pulse without being affected by code execution time
   digitalWrite(stepPin, HIGH);
   delayMicroseconds(5);
   digitalWrite(stepPin, LOW);
 }
}

Thanks MarkT for youryour suggestion , it works fine , low revs high revs , ....i am mechanical engineer , i must stydy deeply the electronics, thanks for your valuable help, thank all the guys offered their help

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