Servo problems.

Development Boards Arduino
1

I am trying to use the Arduino to turn on a servo, move it to a position, then turn the servo back off. I need the servo to be turned off because of power consumption issues among other reasons.

Here is my code

 #include <Servo.h> 
 
Servo myservo;  // create servo object to control a servo 
                // a maximum of eight servo objects can be created 
 
int pos = 0;    // variable to store the servo position 
int Servo = 5;                                        // Servo power connected to pin 5

void setup() 
{ 
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object 
  pinMode(Servo, OUTPUT);                                 // Set a digital pin for the GPS Power
 
} 
 
 
void loop() 
{ 
  digitalWrite(Servo, HIGH);                              // Turn the Servo on
   myservo.write(10);              // tell servo to go to position 
  digitalWrite(Servo, LOW);                              // Turn the Servo off
    delay(1000);                       
       digitalWrite(Servo, HIGH);                              // Turn the servo on  
    myservo.write(105);              // tell servo to go to position 
    delay(1000);                        
 digitalWrite(Servo, LOW);                              // Turn the Servo off
  }

It works when I have the power line connected to the 5v pin on the Arduino however it will not work when it is plugged into pin 5 (or any other pin I set it to for that matter)

I use this same method successfully to power a GPS unit. Any ideas on why it will not work?

I thought maybe adding delays after the servo high and before the servo low might help but it does not.

Pin 5 reads 4.75v

5v Pin reads 4.80v

2

An arduino digital pin can supply ~40mA of current.

Your servo power input needs more than that - your GPS doesn’t

Look for examples that show how to use a transistor to switch high current (or high voltage) lines.

3

ok I got it working with a NPN transistor however even with the power to the transistor off the servo still makes noise. I can stop the noise by gently moving the servo arm (attached to a lock) I will not be able to do this when the unit is in operation. It is so loud you can hear it from several feet away. I don’t care how much noise it makes while it is moving but after it is done then I want it to be quiet. Any Ideas on how to make it quiet?

4

If the servo is making noise, you haven’t powered it down. No power, no noise. I’d start looking there.

5

I measured the voltage and it goes from 4.8v to .01v

I guess the transistor has some leak-through Maybe if I double up on the transistors and then use two digital ports to control the servo.