continuous rotation servo won't turn

This is a special forum devoted to educators using Adafruit and Arduino products for teaching.

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
sirmichaelanderson
 
Posts: 7
Joined: Tue Feb 24, 2015 8:39 am

continuous rotation servo won't turn

Post by sirmichaelanderson »

Hi,
I bought a bunch of FeeTech FS5103R continuous rotation servos from you for the robotics club. When I hook one up to directly to the arduino, it just barely jerks every 1/2 second and it causes my PC to beep repeatedly at me. The jerks are all in the same direction no matter what number I wrote to the servo (0-180). When I hook the servo to batteries, it just jerks once and then nothing at all. I have tried 3 different servos, 4 different Arduinos, and 4 different power supplies (the arduino itself, four AA batteries in series, a cell phone charger with a voltage of 5+ V, a cell phone charger of 6.2 V)

Uggg! Please Help! My code looks like this:

Code: Select all

#include<Servo.h>
Servo Bob

void setup()
{
Bob.attach(13);
}

void loop()
{
Bob.write(60);  // I also tried (0) and other numbers
}

thanks in advance.
-michael

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: continuous rotation servo won't turn

Post by adafruit_support_bill »

When I hook one up to directly to the arduino, it just barely jerks every 1/2 second and it causes my PC to beep repeatedly at me.
Do you see any activity on the Arduino LEDs when this is happening?

Please post a photo of how you are connecting them.

User avatar
sirmichaelanderson
 
Posts: 7
Joined: Tue Feb 24, 2015 8:39 am

Re: continuous rotation servo won't turn

Post by sirmichaelanderson »

Hi again,
When the servo is attached directly to the arduino, the pin13 LED rapidly flashes a few times during the servo jerks. The power LED blinks off once with each jerk. The computer beeps as if the USB was disconnected/connected with each jerk..

Sadly, I can't attach a video of this. Here are two Youtube links to show you

The first is entitled "trouble with my arduino" by Michael anderson
https://www.youtube.com/watch?v=EEqKVvY ... e=youtu.be

the second is entitled "trouble with my arduino part 2"
https://youtu.be/5nypRTImbGM

The videos show the middle hot wire attached to the 5v pin, the brown ground wire to the nearby GND pin, and the orange signal wire to pin 9 (I was wrong about it being 13 before, the code said 9).

thanks for your time and helpfulness
-michael

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: continuous rotation servo won't turn

Post by adafruit_support_bill »

When the servo is attached directly to the arduino, the pin13 LED rapidly flashes a few times during the servo jerks. The power LED blinks off once with each jerk. The computer beeps as if the USB was disconnected/connected with each jerk..
Those symptoms are consistent with an overload-induced processor reset. The power LED blinks because the voltage drops. The Pin13 led flashes as the bootloader restarts.
4 different power supplies (the arduino itself, four AA batteries in series, a cell phone charger with a voltage of 5+ V, a cell phone charger of 6.2 V)
How are you connecting these power supplies to the Arduino? The minimum input voltage when powering via VIN or the DC input jack is 7v.

User avatar
sirmichaelanderson
 
Posts: 7
Joined: Tue Feb 24, 2015 8:39 am

Re: continuous rotation servo won't turn

Post by sirmichaelanderson »

Hello,
(note: I added a bunch of detail here just to have you confirm that I am thinking correctly...I may have made a stupid mistake...my confidence in myself it VERY low....I don't include this info because I think you need it)

With the phone charger, I stripped off the insulation and found 2 wires inside...red and black. My multimeter showed the voltage to be a tad over 5V. By looking at the + and - on the multimeter I confirmed that the red was hot. I connected these wires directly to the servo's red and brown wires. The servo's signal wire was attached to the Arduino pin.

With the batteries, I had 4 regular (NOT rechargeable) AA batteries in series with each other (connecting the wires of the 4 battery holders together in a red-to-black fashion). The 2 wires from the batteries were connected to breadboards blue and red columns. I then connected the servo's brown wire to the blue column and the red wire to the red column. The signal wire when to the pin.

I have used the 9V input before, but I am not familiar with using the Vin or DC input jack. Could you direct me to a place to read about how to use those?

thanks for you patience and time.
michael

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: continuous rotation servo won't turn

Post by adafruit_support_bill »

With the phone charger and battery connections you describe, the one thing missing is a ground connection between the brown wire and the Arduino. This is necessary so you have a common ground reference for the control signal.

But that would not explain the Arduino resets. If your only connection between the servo and the Arduino is the signal wire, there would be no way to overload the Arduino power supply.

User avatar
sirmichaelanderson
 
Posts: 7
Joined: Tue Feb 24, 2015 8:39 am

Re: continuous rotation servo won't turn

Post by sirmichaelanderson »

thank you so much for the education. I will try some changes with the common ground after school today and see what happens.

User avatar
sirmichaelanderson
 
Posts: 7
Joined: Tue Feb 24, 2015 8:39 am

Re: continuous rotation servo won't turn

Post by sirmichaelanderson »

IT WORKS!!!!!

Fantastic! I can't express how much your help is worth. This is not the first time I have gotten outstanding assistance from you folks....so quick and so patient and so clear. You folks have definitely earned my customer loyalty, even though I could buy at lower prices from some factory in China, your helpfulness is worth every dime!

Now, I must get back to my project of conquering the world....

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: continuous rotation servo won't turn

Post by adafruit_support_bill »

Glad to be of assistance. Good luck with your global conquest!

Locked
Please be positive and constructive with your questions and comments.

Return to “For Educators”