Trouble running two servos simultaneously in opposite directions

Using Arduino Programming Questions
1

Hello, I really need some help figuring out how to make this work. I am trying to set my two servos up for a project I am working on so that the first servo goes from 90 to 150 degrees and back, and also a second servo that goes from 90 degrees to 30 and back at the same time. All I get with my code is a twitching of the servos, so any help is greatly appreciated.

Here is my current code:

/* Sweep
 by BARRAGAN <http://barraganstudio.com> 
 This example code is in the public domain.

 modified 8 Nov 2013
 by Scott Fitzgerald
 http://www.arduino.cc/en/Tutorial/Sweep
*/ 

#include <Servo.h> 
 
Servo myservo;  // create servo object to control a servo 
                // twelve servo objects can be created on most boards
Servo myservotwo;  // create servo object to control a servo 
                // twelve servo objects can be created on most boards
 
int pos = 90;    // variable to store the servo position 
int postwo = 90;    // variable to store the servo position 
 
void setup() 
{ 
  myservo.attach(7);  // attaches the servo on pin 7 to the servo object 
  myservotwo.attach(5);  // attaches the servo on pin 5 to the servo object
} 
 
void loop() 
{ 
  for(pos = 90; pos <= 150; pos += 1) // goes from 90 degrees to 150 degrees 
  for(postwo = 90; postwo >= 30; postwo -= 1) // goes from 90 degrees to 30 degrees
  {                                  // in steps of 1 degree 
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    myservotwo.write(postwo);              // tell servo 2 to go to position in variable 'postwo'
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
  delay(5000);
  for(pos = 150; pos>=90; pos-=1)     // goes from 150 degrees to 90 degrees
  for(postwo = 30; postwo <= 90; postwo -= 1) // goes from 30 degrees to 90 degrees 
  {                                
    myservo.write(pos);              // tell servo to go to position in variable 'pos' 
    myservotwo.write(postwo);              // tell servo 2 to go to position in variable 'postwo'
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
}
2

I have not looked at your code but two thoughts spring to mind. The servos need to supplied with at least 5v and directly from a voltage source eg a battery and all the earths need to connected together to function properly if the arduino is powered separately. Regards

3

I apologize for any confusion! Here is a fritzing diagram to give a better representation of how the board setup currently looks that I want to use my code with. Thanks!

Dual Servo Frtitzing.JPG
Dual Servo Frtitzing.JPG1574×798 175 KB

4

Ended up getting help from a friend. For the benefit of everyone who needs it, here is the code to run two mirrored servo motors simultaneously. Enjoy!

/* Sweep
 by BARRAGAN <http://barraganstudio.com> 
 This example code is in the public domain.

 modified 8 Nov 2013
 by Scott Fitzgerald
 http://www.arduino.cc/en/Tutorial/Sweep
*/ 

#include <Servo.h> 
 
Servo servo1;  // create servo object to control a servo 
Servo servo2;  // create servo object to control a servo 
                // twelve servo objects can be created on most boards
 
int pos = 90;    // variable to store the servo position 
 
void setup() 
{ 
  servo1.attach(8);  // attaches the servo on pin 9 to the servo object 
  servo2.attach(7);  // attaches the servo on pin 9 to the servo object 
} 
 
void loop() 
{ 
  for(pos = 90; pos >= 19; pos --){
  servo1.write(pos);
  servo2.write(180-pos);
  } 
  //delay(5000);
  for(pos = 19; pos <= 90; pos ++)     // goes from 19 degrees to 90 degrees 
  {                                
    servo1.write(pos);              // tell servo to go to position in variable 'pos' 
    servo2.write(180-pos);              // tell servo to go to position in variable 'pos' 
    delay(15);                       // waits 15ms for the servo to reach the position 
  } 
}
5 
for(pos = 19; pos <= 90; pos ++)     // goes from 180 degrees to 90 degrees

If the comment doesn't describe the code in a meaningful way, it's better that it's not there at all.

6

the first servo goes from 90 to 150 degrees and back, and also a second servo that goes from 90 degrees to 30 and back at the same time

The clue is in the last 4 words. You need to use a single for loop.

for (int pos = 90; pos <= 150; pos++)
{
  Servo1.write(pos);  // 90 to 150
  Servo2.write(180 - pos);  //90 to 30
  delay(someDelay);  //wait a little at each position
}
7

Powering the servos from the Arduino is NOT good for the Arduino. They suck way more current than the Arduino can safely supply.