I recently bought a "standard" servo motor TowerPro SG-5010.
And set it up according to the instructions in: https://learn.adafruit.com/controlling- ... bone-black
Cannot get the motor to turn.
Tried both as root and as a normal user.
Has anyone got this project to work according to the instructions on the web link?
Could I have a defective servo motor? If so can I get a refund?
Servo Motor problem
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- adafruit_support_rick
- Posts: 35092
- Joined: Tue Mar 15, 2011 11:42 am
Re: Servo Motor problem
Please post some clear, detailed pictures of your connections.
- maranha
- Posts: 4
- Joined: Thu Aug 07, 2014 6:03 pm
Re: Servo Motor problem
Don't have the thing in front of me or a good way to post a picture but verified the wiring several times.
Is there a quick/simple test to verify that the motor works at all?
I think I probably have a DOA motor in which case I'd like to get a refund.
Is there a quick/simple test to verify that the motor works at all?
I think I probably have a DOA motor in which case I'd like to get a refund.
- weldeng
- Posts: 5
- Joined: Wed Aug 13, 2014 9:36 pm
Re: Servo Motor problem
I am having the same problem. I have tried two different servos Tower Pro SG-5010 ad smaller SG-90. Neither rotates. I set up following the Adafruit tutorial instructions. I have Rev C board with Debian.
- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Servo Motor problem
Please post photos showing your connections.
Do your servos make any noise or twitch at all when first connecting power?
Do they hum or vibrate at all when powered?
When not powered, are you able to turn the shafts by hand with moderate resistance?
Do your servos make any noise or twitch at all when first connecting power?
Do they hum or vibrate at all when powered?
When not powered, are you able to turn the shafts by hand with moderate resistance?
- maranha
- Posts: 4
- Joined: Thu Aug 07, 2014 6:03 pm
Re: Servo Motor problem
Answers to all above questions is: no.
The motor appears to be dead.
The motor appears to be dead.
- adafruit_support_bill
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- Joined: Sat Feb 07, 2009 10:11 am
Re: Servo Motor problem
@marhana - please contact [email protected] with a link to this thread for a replacement TowerPro SG-5010.
- tdicola
- Posts: 1074
- Joined: Thu Oct 17, 2013 9:11 pm
Re: Servo Motor problem
For folks that are still running into this issue with good servos, I found you might need to invert the polarity of the PWM signal to make it work. I updated the guide page to call out that you can pass an optional 4th parameter to PWM.start with a value of 1 to invert the signal. Take a look at the updated page here and give it a shot to see if it works: https://learn.adafruit.com/controlling- ... on-console
- weldeng
- Posts: 5
- Joined: Wed Aug 13, 2014 9:36 pm
Re: Servo Motor problem
weldeng wrote:I am having the same problem. I have tried two different servos Tower Pro SG-5010 ad smaller SG-90. Neither rotates. I set up following the Adafruit tutorial instructions. I have Rev C board with Debian.
I fixed the problem. On starting the program the motor would rotate fully counterclockwise and would not budge thereafter. Changing two lines of your code fixed the problem. Corrected code is provided below.
PWM.start(servo_pin, (100-duty_min), 60) changed to PWM.start(servo_pin, duty_min, 60)
and
duty = 100 - ((angle_f / 180) * duty_span + duty_min) was changed to duty = ((angle_f / 180) * duty_span + duty_min)
Thanks
- weldeng
- Posts: 5
- Joined: Wed Aug 13, 2014 9:36 pm
Re: Servo Motor problem
tdicola wrote:For folks that are still running into this issue with good servos, I found you might need to invert the polarity of the PWM signal to make it work. I updated the guide page to call out that you can pass an optional 4th parameter to PWM.start with a value of 1 to invert the signal. Take a look at the updated page here and give it a shot to see if it works: https://learn.adafruit.com/controlling- ... on-console
I am curious as to why some servos need the polarity inverted and some dont? Would it vary between two servos of the same model, for example the Tower Pro SG-5010 I used vs the SG-5010 used in the Adafruit tutorial?
Thanks
- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Servo Motor problem
It is not a servo problem. It appears to be due to some library change in recent BBB releases.
- tdicola
- Posts: 1074
- Joined: Thu Oct 17, 2013 9:11 pm
Re: Servo Motor problem
Yep servos always want the same signal, but my suspicion is that perhaps the older Angstrom OS had different behavior with PWM compared to Debian.
- maranha
- Posts: 4
- Joined: Thu Aug 07, 2014 6:03 pm
Re: Servo Motor problem
@tdicola, @adafruit_support_bill - thanks!
I was about to send photo and/or return servo but Inverting polarity worked.
@weldeng - have not tried your approach yet.
I have to be 'root' to get program to work.
Looks like libraries need updating!
I was about to send photo and/or return servo but Inverting polarity worked.
@weldeng - have not tried your approach yet.
I have to be 'root' to get program to work.
Looks like libraries need updating!
- nick_karam
- Posts: 4
- Joined: Fri Oct 10, 2014 10:47 am
Re: Servo Motor problem
I have the same problem though inverting polarity did not fix it. MICRO-SERVO SG90
-Do your servos make any noise or twitch at all when first connecting power? No.
-Do they hum or vibrate at all when powered? No.
-When not powered, are you able to turn the shafts by hand with moderate resistance? Yes.
The commands by the console are sent with no error feedback and the program too.
It just won't reply. Any suggestions? Thank you in advance.
-Do your servos make any noise or twitch at all when first connecting power? No.
-Do they hum or vibrate at all when powered? No.
-When not powered, are you able to turn the shafts by hand with moderate resistance? Yes.
The commands by the console are sent with no error feedback and the program too.
It just won't reply. Any suggestions? Thank you in advance.
- adafruit_support_bill
- Posts: 88096
- Joined: Sat Feb 07, 2009 10:11 am
Re: Servo Motor problem
What are you using for a power supply for the servo? Post a photo of how you have it hooked up.-Do your servos make any noise or twitch at all when first connecting power? No.
-Do they hum or vibrate at all when powered? No.
Please be positive and constructive with your questions and comments.