Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?
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Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by xoundbox on Fri Aug 30, 2013 5:05 pm

I'm having power problem with the shield. Eventually I will stack up 4 of this shield with 64 servos for my art work but before connecting all, I tested 16 servos with one shield. I uses Tower Pro MG90S high torque metal gear servos(http://www.adafruit.com/products/1143) and 5V 2A power supply(http://www.adafruit.com/products/276).

I'm not sure if it's only my case but I bought already 4 x 5V 2A power supplies with no doubts, which is recommended on tutorial page as one of good power choices.(There was no detailed description for power supply in the links before) I reported about it this early morning and now more detailed description has added such as how many servos can control for each power supply.

Thank you for adding it as fast as you can for others who has not much experience of high torque servo and just follow purchase links like me. But...

    1. I already bought 4 x 5V 2A power supplies :oops: and it happened already to me. Is there any way to use them? I just need to return it? And buy 4 x 5V 10A (http://www.adafruit.com/products/658)? It will be enough? Needs more amps?

    2. I'm curious if it was ok when Adafruit tested out this shield with fully running 16 high torque servos. If it was ok, I'm curious what power supply they used?

    3. I'm using MG90S servos as I mentioned above. Can you suggest which power supply will cover all fully? I need to run all the servos all the time and sometimes they will move in high torque at once.

    I have another 5V 2A power supply from other product and it works better and can control 16 servos but it's unstable and not enough power at some point.(buzzing, stopping, moving randomly, some servos are very very hot.) It says 5V 2A but when I checked it meter reads about 11A at the beginning then few seconds later it drops to about 2A. So it seems it's not the solution.

    4. I read about adding capacitor (n*100uF). So should I use about 1600uf for this kind of heavy project? I'm not sure if the capacitor exists.

Any suggestions to make this project work? I don't wanna burn my 4 shields and 64 servos.
This is an urgent project but I'm stuck on this powering stuff which I believed the shield can control 16 servos fully. So I'll appreciate if anyone can give suggestions it as soon as possible.

Thanks in advance.

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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by franklin97355 on Fri Aug 30, 2013 5:37 pm

The power requirements will depend on the loads you are controling and how fast and how many servos you are moving at one time. What are you trying to move, what does it weigh and how far from the servo hub will it be? Depending on your specifications you could use a 6v battery.
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by xoundbox on Fri Aug 30, 2013 7:03 pm

16 servos runs at one time on each shield. Very light moves - small pieces(1.5"x1.5"x3") of wood on smooth surface without any other frictions. There is no other extension wires from the servo shield. Yeah I tried to use 6v battery pack and it works slightly better but not the solution. :/

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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by adafruit_support_bill on Fri Aug 30, 2013 7:10 pm

I'm having power problem with the shield.

What exactly is the problem you are experiencing?
I reported about it this early morning

I only see 2 posts associated with your account - both of them are in this thread.
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by xoundbox on Sat Aug 31, 2013 10:57 am

What exactly is the problem you are experiencing?

I realized 5V 2A power supply can't draw enough power to all 16 servos fully. It seems there is no problem up to 4 - 8 servos.
After connecting 16 servos when I turn on power for servos, all servos will try to move at the same time and green light is almost dimmed out. After removing some of them, then it works properly. Even with example code('servo'), there is same issue. So I'm sure 5V 2A power supply is not good choice for 16-Channel 12-bit PWM/Servo Shield as the tutorial mentioned because I don't think someone wants to buy this shield with limited servos. But I already ordered 3 more 5V 2A power supply and it's coming soon. So I'm asking those couple of questions.

I only see 2 posts associated with your account - both of them are in this thread.

Yeah. I sent the feedback in the tutorial section only (I don't have original post since there is no copy or reply.) because there was no mentions about if each power supply gives enough power. So I assumed someone like me will buy 5V 2A power supply without any doubt. Now there are additional comments as and some phrases are bolded, which I asked. http://learn.adafruit.com/adafruit-16-channel-pwm-slash-servo-shield/shield-connections
Good power choices are:
5v 2A switching power supply (up to perhaps 4 servos)
5v 10A switching power supply (up to perhaps 16 servos)
4xAA Battery Holder - 6v with Alkaline cells. 4.8v with NiMH rechargeable cells, portable!
4.8 or 6v Rechargeable RC battery packs from a hobby store.

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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by adafruit_support_bill on Sat Aug 31, 2013 11:27 am

There is no one-size-fits-all solution. Servo current requirements vary greatly depending on the servo type, load and activity. I have 10 sub-micro (LS-0003) servos running from a 1A supply right now. But my 3DOF hexapod robot (18x high torque servos) needs about 8A.

If you wish to exchange your 2A supplies for a 10A supply, please contact support@adafruit.com with a link to this thread and your order information.
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Servo Shield?

by xoundbox on Mon Sep 02, 2013 11:05 am

Thank you for letting me know about the robot. I guess I also need 10A supplies for 4 x 16 high torque servos. Let me send an email to support@adafruit.com.

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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by xoundbox on Mon Sep 30, 2013 1:41 am

Here is what I've done with four of 16-Channel 12-bit PWM/Servo Shield. 5V 4A power supplies works for this project.

https://vimeo.com/75616621

Enjoy! :)

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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by adafruit_support_bill on Mon Sep 30, 2013 6:44 am

That's great! Thanks for posting :D
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by gomezrjo on Mon Sep 30, 2013 10:23 am

Hi,

I have a similar question about this shield. Here is the background information:

I'm planning to build an hexapod robot and I think I'll use the 16-Channel 12-bit PWM/Servo Shield to control the 12 servos involved in my project, so I'm interested to hear the power source Adafruit_Support_Bill is using for his 3DOF hexapod robot to make sure I have the right power source. The documentation mentions that a 4xAA batteries holder can be used to power the shield, is this what you are using in your project, or do you have an special arrangement to satisfy the 8A requirement?

In a similar note, form the video posted on the product page, it seems the Arduino has its own power supply and the shield has its own external power, is this correct? Do you have more details about the wiring for the external power? From other forums, the Arduino Ground needs to be connected to the external power, I assume this is the same here, correct? Additionally, does the shield provides this automatically since it is stacked to the Arduino?

Thanks in advance for your feedback.
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by adafruit_support_bill on Mon Sep 30, 2013 10:34 am

The shield provides a common ground for the external power supply. You just need to connect your supply to the external power screw-terminals on the shield. For my hexapod, I use a 3500mAh 7.2v NiMH pack. These are available from Radio Shack or any hobby shop that carries radio-control gear.

Most servos are rated for 6v max. Overvoltage will give you more torque - but you can expect a shorter lifespan. Not all servos can handle the overvoltage. I am using HiTec HS645MG.
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by gomezrjo on Mon Sep 30, 2013 9:02 pm

Hi,

Thanks for your response. This is very helpful. I'll check the servos specs to validate the overvoltage situation.

And one last question related to the power supplies. The external power supply connected to the screw-terminals on the shield will only power the shield and therefore I need to use my regular 9V battery to power the Arduino board, correct?
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Re: Any suggestions for powering to 16-Channel 12-bit PWM/Se

by adafruit_support_bill on Mon Sep 30, 2013 9:09 pm

The external power connection on the shield powers only the servos. You will need a separate supply to power the Arduino as well as the logic circuits on the shield. A 9v battery is fine. Any supply between 7v and 12v will work.
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