
Motorola Moto 360 Teardown - theoutlander
https://www.ifixit.com/Teardown/Motorola+Moto+360+Teardown/28891
======
jwise0
Two things that are relatively surprising for me from the teardown.

One, I'm surprised that they include a USB PHY on board. Given that the
machine has no externally accessible USB interface, that seems like a waste of
power, BOM cost, and board area. The only thing I could imagine it being used
for is through the mystical 5-pin programming header, for initial device
programming; even still, I would imagine they'd prefer to cost-reduce and use
JTAG (or another glueless interface) to do initial programming.

I could imagine that they'd use it for bringup, but even still, it seems like
they'd want to have a non-bringup SKU for mass production that didn't have the
USB PHY populated, and would just drop down the part if needed...

The other surprise was the MIPI DSI-DSI bridge. Having a DSI-DSI bridge that
supports panel self-refresh allows them to keep the display alive even without
having the OMAP (and its DRAM) turned on. The bridge seems to have 28Mbit of
SRAM on it as a frame buffer, though, and that can't be cheap: I suppose the
learning is that on OMAP, even keeping the DRAM powered on for a minimal
refresh is more expensive in terms of power than a big external bridge.

Additionally, I'm vaguely curious about the external DSP; I wonder what
they're doing with it? It's probably some operation to save power while the AP
is turned off, but I wonder just how much power it really can save.

Neat device. It'll be interesting to hear the explanations of how people
designed these first gen devices as they show up over the next decades.

~~~
jmgrosen
They might be using the DSP for the "OK Google" hotword detection -- at least,
that's what they used on the Moto X 2013 (not sure about this year's).

~~~
pkulak
Hot word detection is not always on with the 360. Gesture recognition is,
though. I'd put my money on that.

~~~
andygates
It's on when the screen is illuminated, which is "always" for most intentional
use.

~~~
pkulak
What? It's only on for about 3 seconds when you are looking at it.

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cnbuff410
Here's Motorola's statement:

The typical battery capacity for Moto 360 is 320 mAh and the minimum is 300
mAh. In the mobile industry, sometimes both the minimum and typical capacity
is listed on the battery, with the typical capacity quoted as the official
battery size. Both figures are included on the batteries of our Moto X, Moto E
and Moto G devices. In the case of smaller devices, we aren’t always able to
list both figures. For Moto 360 we only had room for one figure and choose to
list the minimal capacity of the battery. We see how this can be confusing and
we will look into ways to add the typical capacity as well in the future.

~~~
makomk
For anyone who hasn't paid close attention to the gory details of battery
specs, this is pretty normal - most of them have both a typical and a minimum
capacity. Which one gets advertised is mostly a marketing decision.

~~~
tgb
What's the difference? (Or rather: why don't they know the exact value?)

~~~
Igglyboo
Probably manufacturing differences and legal reasons. If the average battery
life is x and someone gets a battery they can prove is x - 50 they might get
sued, where as if they put a generous minimum battery life they can cover
their asses.

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TheMagicHorsey
Did I hear that right? Did they say OMAP 3? I didn't know anyone was still
using OMAP3 outside of charity organizations trying to provide very basic
tablets to children living in terrible conditions in the third world.

Why they gotta be so cheap on their flagship smartwatch?

~~~
ansible
_Why they gotta be so cheap on their flagship smartwatch?_

More expensive also tends to imply more processing power, which also implies
more power consumption.

More is not better, considering what's going to fit on your wrist.

Also, with an older platform, if they've had time to work out all the issues
and greatly refine the power management (so that everything stays active for
only as long as necessary), it can end up using less power than a SoC that
uses a better process technology but doesn't have as good software support.

~~~
TheMagicHorsey
Its not like OMAP4 is some lightly used, power-hungry, and untested platform.

~~~
ansible
It is physically larger, and costs more. It has a ton of I/O, supports high
resolution cameras, can do HD video recording, encoding and decoding.

So what exactly is the justification that a watch needs all that? What is the
OMAP3 missing that you think a watch needs?

~~~
TheMagicHorsey
Have you seen the size of a Moto360? It is thick!

The Apple Watch is much slimmer. Part of the reason for that is the SoC that
Apple uses is more modern and compact than OMAP.

OMAP3 isn't the best processor to use for a watch. I'm sure if we spend some
time going back and forth we will identify at least one or two more modern
processors that beat OMAP3 on efficiency, size, AND performance.

I don't thin Motorola should be skimping on the processor for their first
watch, if they are trying to convince us its a premium product that we should
feel proud to wear on our wrists. People see watches as prestige items, and
they will pay more for a well constructed and designed device. There's already
enough competition in the plastic trashy wrist-wear segment.

~~~
ansible
_Have you seen the size of a Moto360? It is thick!_

Both the OMAP3 and OMAP4 are 12mmx12mm BGA packages, with pop-memory (package
on package). This does add to the height, but the alternative is to put the
SDRAM on the board which chews up a lot of board real estate.

 _OMAP3 isn 't the best processor to use for a watch._ ... _I don 't thin
Motorola should be skimping on the processor for their first watch,..._

You still haven't explained what the OMAP3 watch doesn't do now, that it could
do with an OMAP4.

 _There 's already enough competition in the plastic trashy wrist-wear
segment._

That's actually likely to be a problem with the Apple watch too. If it doesn't
prove to be too popular, then will future versions of iOS support it? Sure, 8
will, and possibly 9. But after that? In a couple years there will be a watch
with some other whiz-bang feature and everyone will want to upgrade to that.

These tiny wearable computers will suffer just as much obsolescence as our
phones do. A Seiko mostly just tells time, and the standards for don't change
much.

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guelo
How do you program the circular screen on this thing? Is it a radial
coordinate system (which would make it hard to draw parallel and perpendicular
lines). Or is it a rectangle but you have to keep track of when you're inside
the circle? Or maybe you're not even allowed to draw on the thing and you have
to use higher level api functions?

~~~
ZoFreX
As the other poster said, it's a square with bits cut off. You can program it
per pixel if you want to, but for most typical use-cases developers will be
using higher level APIs that handle the details for you.

You can try out developing for both the square and round screens for free
using the provided emulators:
[https://developer.android.com/training/wearables/apps/creati...](https://developer.android.com/training/wearables/apps/creating.html)

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dang
Url changed from [http://arstechnica.com/gadgets/2014/09/ifixit-cracks-open-
th...](http://arstechnica.com/gadgets/2014/09/ifixit-cracks-open-the-
moto-360-finds-smaller-battery-than-advertised/), which points to this.

~~~
swang
This bit from ifixit about the battery saying 300mAh vs 320mAh is about a day
or two old, but ArsTechnica is the one who got the actual
clarification/explanation from Motorola.

~~~
dang
Should we change the URL back?

~~~
Navarr
I think so, so the user doesn't have to read the comments to get the full
understanding.

~~~
raphman_
As ifixit included Ars' update in their teardown, there is no need to switch
back.

