OpenServo.com

ahoeben · Joined: 20 Jun 2008 Posts: 20

http://www.sparkfun.com/commerce/product_info.php?products_id=9014

Looks like SparkFun did their own version of the OpenServo boards. They look a bit less finicky, but that could just be the pictures. Does anyone have any more details about this version?

update: Looks like its based on the V2 branch...
I came to OpenServo in the V3 era, what functionality is missing in the V2 branch of the hardware?

update: Answering my own question, from http://www.openservo.com/OpenServoV3
# Back EMF speed sensing
# Braking
# Temperature sensor
# 20MHZ clock speed / 400khz interface

ginge · Posted: Fri Jul 10, 2009 8:05 am Post subject:

Good find!

This is the first I have heard about this.

Indeed it is based on the old v2 branch. There are numerous other features int he v3 that you have not listed.

Strangely, the v2 branch, although functional, is no longer supported. I wonder how long it is before we get people on here asking for support.
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jharvey · Posted: Sat Jul 11, 2009 12:33 am Post subject:

Sweet, out of stock.

ginge · Posted: Fri Aug 28, 2009 9:21 pm Post subject:

An update to this thread...

I had a friendly chat with the main man over at SparkFun and we have come to a gentlemans arrangement.

As of fairly soon, the v2 branch will be slightly revived so we can backport some of the v3 shiny features. We don't have much room to play with in the atmega 8 so I will be drawing up a sortlist of features that are useful.
I am also going to look at the documentation for the v2 branch, and make sure it is up to scratch.

We will also be addind a link and image on the front page to the SparkFun product. If they can sell a few units, we gain a larger userbase. Win-win.
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jharvey · Posted: Sat Aug 29, 2009 10:24 am Post subject:

Nice, I haven't looked at the V2 board much. Should I put in a plug to have some extra pads left there for a possible future upgrade that allows Open-Encoder?

FireBALL · Joined: 24 Jul 2009 Posts: 28

Sadly I bought 4 of those without realising the difference. Though i was able to load FW3 but motor is sluggish and feedback response is somewhat confused rather messed up. can any one suggest what can I do with those boards. Is there anyone with extra PCBs of v3 I don't mind hand soldering. I need four.

ginge · Posted: Sat Aug 29, 2009 4:04 pm Post subject:

fireBALL,

you could always buy a v3 from the robotfuzz webshop

http://www.robotfuzz.com/OSv3

cheers
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http://www.robotfuzz.co.uk/

FireBALL · Joined: 24 Jul 2009 Posts: 28

Cheers Ginge

any plans of introducing new ones with incremental encoder support? It would be a great idea to have an option of resetting '0' position

OT - have a look at this, might be a good replacement for pots. It's a miniature absolute encoder by Usdigital, and should not be difficult to fit inside a servo

jharvey · Posted: Mon Aug 31, 2009 8:59 am Post subject:

That is a nice device, unfortunately I don't see how it could be used in a RC servo. Most servos have either a D shaft or two flats on the shaft. It appears you can get this with a couple different diameters, but can't get it with flats.

$36/ea is also interesting.

FireBALL · Joined: 24 Jul 2009 Posts: 28

I tried dremel with a grinding stone on a precision solid steel rod and was able to get the right flat surface.

Once I receive my encoders I'm going to do the same on them, will post a picture if I manage to do it.

jharvey · Posted: Mon Aug 31, 2009 4:11 pm Post subject:

Do you know what the shaft is made of? Looks like it might be the magnetic materail. If so you might want to take some precautions. Grinding magnetic materail can cause magnetic dust that is known for some nasty issues when air born. I think it was mostly the Colbalt, but I forget what the issues are exactly. With luck, it will turn out to be steel or something pleasant to modify.

Keep us posted.

FireBALL · Joined: 24 Jul 2009 Posts: 28

That's a good thought but it can't be magnetic, that will lead to other kind of operational and manufacturing problems.

In any case I'm going to write to them and ask.

thank you for the input. much appreciated.

Ginge*** any possibilities of early christmas this year? (any discounts on 3 OpenServo V3 boards)

cheers

ginge · Posted: Tue Sep 01, 2009 8:14 am Post subject:

FireBALL · Joined: 24 Jul 2009 Posts: 28

FireBALL · Joined: 24 Jul 2009 Posts: 28

ginge >> I ordered one yesterday but didn't get any confirmation after paypal routine, hope it's all ok and the board is on it's way Smile

cheers