Controlling a servo motor does not work (hopefully an easy one)

Using Arduino Motors, Mechanics, Power and CNC
#1

Hi,

I am trying to control my servo.
I have an Arduino Diecimila board, the servo is called SERVO POWER HD 6001HB (bought here http://www.bricogeek.com/shop/motores/251-servo-power-hd-6001hb.html).

I have attached the red cable to the 5V, the brown cable to the ground and the yellow cable to pin 3.

Now if I run the example code, the Sweep sketch, it works, the servo slowly turns 180 degrees and back.
But if I try to run such a simple sketch:

#include <Servo.h> 

Servo servo1;

void setup() 
{ 
  servo1.attach(3);

  servo1.write(0);
  delay(5000);
  servo1.write(30);
  delay(5000);
  servo1.write(70);

  servo1.detach();
}

void loop() 
{  }

it doesn’t work. Sometimes it does not move, some others it moves just once, some others it moves a bunch of times like in a random way.

I have tried to check the sequence of commands by adding some Serial.println() and I have seen strange things, the delays are not respected (while in other situations they work) and the lines sometimes are printed in a strange order .

Any idea?

thanks…

#2

You are not trying to power the servo from the Arduino's 5V pin are you? That's not good, servo's take several amps peak, way more than the Arduino regulator (or a USB socket) can handle.

#3

That probably explains it, I am in fact powering the servo with the Arduino (Arduino powered by the USB).

I have followed this tutorial http://blog.bricogeek.com/noticias/tutoriales/tutorial-control-de-servomotores/ but there the servo is different and the Arduino is the Mega edition. I will try with an external power source and let you know..

Thanks !

#4

Hi,

Check the links in my signature for how and why.

Duane B

rcarduino.blogspot.com

#5

Thanks to both of you, these posts from DuaneB are actually very good. Now My servo is working correctly.

That recommendation about using a common ground between the power source of Arduino and the exernal one fro the servos has avoided me some headhackes :D

#6