#include <Servo.h>

Servo myservo;  // create servo object to control a servo
Servo myservo2;

int potpin = D0;  // analog pin used to connect the potentiometer
int val;    // variable to read the value from the analog pin
int val1;
int val2;
int servo = D4; // D10 is NOT PWM pin
int servo2 = D5; // D0 to D9 are PWM pins

void setup() {
  Serial.begin(9600);
  myservo.attach(servo,500,2400);
  myservo2.attach(servo2,500,2400);  // attaches the servo on pin (servo2) D9 to the servo object, min pulse width, max pulse width
// min (optional): the pulse width, in microseconds, corresponding to the minimum (0 degree) angle on the servo (defaults to 544)
// max (optional): the pulse width, in microseconds, corresponding to the maximum (180 degree) angle on the servo (defaults to 2400)
}

void loop() {
  
  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
  Serial.println(val);

  val1 = map(val, 0, 1023, 100, 30);   // scale it to use it with the servo (value between 30 and 100 degree)
  val2 = map(val, 0, 1023, 30, 100);
  myservo.write(val1);  
  myservo2.write(val2);                // sets the servo2 position according to the scaled value
  delay(15);                          // waits for the servo to get there
}