Re: Servo Board - Available Publicly

[Richard Barnette]

-chromium-os-reviews
+chromium-os-dev

chromium-os-reviews is only for code reviews.
chromium-os-dev is for engineering topics.


On 8/28/14, 12:37 PM, Tom Hennen wrote:
> I'm interested in doing some low level Chromium OS development. I've
> seen references to the Servo board being used to control various aspects
> of the devices include Fully Automated Firmware Tests, boot order
> selection, etc...
>
> Despite the board being referenced in many places on chromiumos.org it
> never says if it is or isn't available publicly.
>
> Is the servo board available publicly? How could I get one?
>
The servo board isn't a publicly available product.


> What about the schematics and firmware?
>
The schematics aren't public. The software for driving
the board is part of the public sources; there's no
on-board firmware.

I note that as a practical matter, actually attaching a
servo to a Chrome OS device requires opening the case,
soldering a connector, and generally voiding your warranty.


> Thanks,
>
> Tom
>
>

--jrb

[Tom Hennen]

My apologies for posting to the wrong spot. I must have been in too much of a hurry.

This would be for a research project.  Opening the device, soldering a connector and voiding the warranty aren't a problem.

Is there anyone that I could contact about potentially getting a servo board for this project?

Thanks again,

Tom

[John Floren]

I'm in the same situation, working on a research project where
soldering a connector would be fine.

Heck, if somebody could point me toward the UART pins on a peppy or a
peach pit, that would be a good start

john

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[Mike Frysinger]

On Thu, Aug 28, 2014 at 1:35 PM, Richard Barnette <jrbar...@chromium.org> wrote:

On 8/28/14, 12:37 PM, Tom Hennen wrote:

I'm interested in doing some low level Chromium OS development. I've
seen references to the Servo board being used to control various aspects
of the devices include Fully Automated Firmware Tests, boot order
selection, etc...

Despite the board being referenced in many places on chromiumos.org it
never says if it is or isn't available publicly.

Is the servo board available publicly?  How could I get one?

The servo board isn't a publicly available product.

What about the schematics and firmware?

The schematics aren't public.  The software for driving
the board is part of the public sources; there's no
on-board firmware.

i thought we made the servo's ourselves.  what would it take for us to publish the schematics ?

-mike

[Simran Basi]

+davidchang who I believe made the schematics.

--

[Bill Richardson]

On Fri, Aug 29, 2014 at 1:53 PM, Mike Frysinger <vap...@chromium.org> wrote:

i thought we made the servo's ourselves.  what would it take for us to publish the schematics ?

​We've asked asked this question about once a year for at least three years that I recall. The answer I've always gotten is that there's nothing secret about servo, but we don't have any way to sell the things externally and no one has taken the time to look into it further.

​

 

​Bill​

--

Art for Art's Sake

Engineering for Money

[Bill Richardson]

On Friday, August 29, 2014 1:49:12 PM UTC-7, John Floren wrote:

Heck, if somebody could point me toward the UART pins on a peppy or a
peach pit, that would be a good start 

I think the Peppy motherboard connector is an "AXK750347G". If so, then the UART pins should be

pin 33 = EC UART TX

pin 32 = EC UART RX

pin 17 = PCH UART TX

pin 16 = PCH UART RX

All at 3.3 volts

Scope it to be sure. The EC console should be active and print things as it boots. The kernel doesn't normally print anything to its serial port.

[Richard Barnette]

On 8/29/14, 2:26 PM, Bill Richardson wrote:
> On Fri, Aug 29, 2014 at 1:53 PM, Mike Frysinger <vap...@chromium.org
> <mailto:vap...@chromium.org>> wrote:
>
>
> i thought we made the servo's ourselves. what would it take for us
> to publish the schematics ?
>
>
> ​We've asked asked this question about once a year for at least three
> years that I recall. The answer I've always gotten is that there's
> nothing secret about servo, but we don't have any way to sell the things
> externally and no one has taken the time to look into it further.
> ​

Yeah, I'd expect that selling servo isn't going to happen.

Still the question is: Can we publish the schematics, or other
technical details?

> ​Bill​
> --
> Art for Art's Sake
> Engineering for Money
>

--jrb

[Olof Johansson]

The approach we've been having lately is to instead make it easier to debug the systems without servo (it'll take a while to reach all the way there).

We've also been improving some of the designs by making sure there are solder pads available for the tx/rx lines for someone to attach wires if needed, but it's a little hit and miss from platform to platform.

Note that some vendors have nostuff resistors that means that the UART lines on the servo connector are disconnected on the mass-produced products, so you might need to do more than just adding the connector and finding the right cable and adapter at the other end.

-Olof

[Shawn N]

Yes we can! Servo schematics + board layouts + misc. technical details are now up on chromium.org:

http://www.chromium.org/chromium-os/servo

For community members -- if additional info about servo would be helpful, please let us know and we'll try to get it up on that page.

 

​Bill​
--
Art for Art's Sake
Engineering for Money

--jrb