// Forum: https://forum.arduino.cc/t/how-to-move-2-servos-in-different-directions-with-speed-control/1091643
// This Wokwi project: https://wokwi.com/projects/356961353402635265

#include <Servo.h>

Servo myServo1;
Servo myServo2;

unsigned long interval = 15; // servo update every 15 ms.
float position = 0;
float delta = 1.0;           // controls direction and speed

void setup() 
{
  myServo1.attach(5);
  myServo2.attach(6); 
}

void loop() 
{
  // Read the potentiometer and convert it to the delta value.
  // Keep 'delta' positive or negative to continue in the same direction.
  // I don't know the maximum speed of the servo motor, the value
  // of 150 was choosen because it looked good.
  int rawADC = analogRead( A0);
  if( delta > 0.0)
    delta = (float) rawADC / 150.0;
  else
    delta = -((float) rawADC / 150.0);

  // Set the new positions of the servo motors.
  myServo1.write( (int) position);
  myServo2.write( (int) (180.0 - position));

  // Calculate new position.
  position += delta;
  if( position > 180.0)
  {
    delta = -delta;
    position = 180.0;
  }
  if( position < 0.0)
  {
    delta = -delta;
    position = 0.0;
  }

  // Slow down the sketch to run the loop every 15 ms.
  delay( interval);
}