robust GPS device

Wolfgang Spraul wolfgang at
Wed Mar 10 03:04:39 EST 2010


> You may know the OpenStreetMap project (it just received the Linux New
> Media award in the category "Most Innovative Open Source Project"

I don't think there is a single person on this list who would not know
about OSM! :-)

> Sadly there is no open GPS hardware available at all.

Sure, and from what I can see it is becoming even more closed, with GPS
functionality moving into the SoC, and sometimes even over to the desktop.
For example I have seen cameras where the camera only logs raw GPS data,
and the actual position is calculated later on the desktop. Implemented
with proprietary software, Windows and Mac only, etc.

> Most people buy Garmin devices because there is some hacky way to install
> custom maps, but no way to change the firmware.

Actually I just bought an old Garmin etrex-H device, because I was
interested in the user interface, waterproof case, etc.
Which Garmin device is the most popular among OSM contributors now?

> Of course there are microcontrollers and GPS chips out there, but a
> little electronics project can not reach the quality of a Garmin device.
> The requirements are:

In another mail, you pointed me to this interesting PDF document
(unfortunately in German only):

The problems in making a low-cost, nicely integrated end user ready device
are only economic. Money :-) Look at the PDF

page 16: small USB/u-blox board only: 60 EUR
page 17: similar board, in very basic (probably non-mobile) case: 300 EUR
page 20: whole setup built out of Beagleboard and other parts,
         unmobile, no case: 420 EUR

If you want to make a nicely integrated mobile device, with robust/polished
software and waterproof case, someone needs to invest at least a few hundred
thousand USD. How to make it back?
One way would be the OpenPandora way of asking OSM contributors to pre-order
and pre-pay, and then build their dream device for them. There are huge
risks with this approach as the 1.5 year waiting time at OpenPandora shows.
As long as the risks are understood by all participants, it's an option.

Let's look at your list:

> - long battery time (32h with 2xAA battery [2])

Hard. How long does the LCM need to be on? How long is backlight on?
To reach such numbers requires a fully integrated design that is optimized
towards power consumption from day 1, and top to bottom.
Ingenic (the supplier of the SoC in our Ben NanoNote) works on a new CPU
with integrated GPS, that's an option I could look at. We would need to see
how low we can clock that CPU, and what the lowest power LCMs are.

> - water proof (fell into the river while canoeing, was still working
>   under water)

AFAIK none of us has experience with waterproof cases, so that would
require some learning. At least we all like to learn new things :-)
I'll start exploring next time I'm in Shenzhen. If someone has experience
with waterproof cases, please holler...

> - accessories like bike mount, hiking backpack clip (bike mount fits the
> clip on the bottom of the device and is more stable than other mounts)

Totally separate from device. As usual if you want good quality you may
have to spend quite some time and money to find the right supplier.

> - SDHC slot (remember water proof)

Probably needs to be inside somewhere, then it shouldn't be a problem.

> - GPS chip


> - b/w or color screen (no touchscreen, just a few buttons)

Good to know b/w is enough, goes back to power consumption requirement above.

> - possibility to write software for this device

Well that one is implicit in anything we do :-)

> Do you think Qi hardware is able to provide a GPS device of such quality
> for similar prices (below EUR200)?

Yes and no.
For one we are currently focusing on software and marketing of our first
product, the Ben NanoNote. If we are unsuccessful in gaining at least some
traction it will get very hard for us to continue as a hardware business.
So that has priority now.
Then we are working on the future by adding an FPGA to the NanoNote board,
and by supporting an entirely FPGA-based computer (Milkymist One). And
we are thinking about the next generation Ya NanoNote, maybe with GPS?
But it would still be a keyboard/clamshell device I would say. Definitely
not to replace something like the dedicated outdoor Garmin GPS devices.

The reason I am personally interested in GPS is that from all the big
RF interfaces right now (GSM/3G, Wi-Fi, Bluetooth, GPS), I think GPS is
the one that will stay around the longest, and the protocols won't be
touched, definitely not in a backward-incompatible way.
I think GPS is built into way too many 'things' in the whole world,
including massive amounts of military gear, so finally this 'installed
base' does something good for us in providing stability of this protocol.

>From a free software perspective, building a GPS device tailored for a
passionate and growing group like OSM contributors makes sense.
We could try to find GPS chips that are as 'thin' as possible and allow
us to implement as much as possible of the GPS protocols in free software.

I don't know much about the state of free software in implementing GPS
protocols and calculations. Maybe the RTKLIB project you pointed out to me
is one of them?

The u-blox chips, as nice as they are, just implement an interface to
receive final GPS coordinates from the module. The module essentially is
a little computer, with memory, flash, CPU. And unfortunately the forces
of integration in consumer electronics force such separate modules to
merge with the other chips on the board, of course not resulting in them
being opened up, but all of it becoming one larger closed blob.

Having said all this, below 200 EUR is no problem, we are setup in such
a way that we try to combine free software and Chinese manufacturing
together, so if things work out the result should be cheap open devices,
like the 99 EUR Ben NanoNote.

> Possible customers would be OpenStreetMap contributors, Geocachers and
> all kinds of outdoor sports guys.

Yes sounds good. Do you have any idea how many people this might be?
Let's assume the software still has some rough edges, how many do you
think we could sell in the first 12 months?

> Maybe you could even get contracts with tourism industry
> for "electronic tour guides".

I would push that back, usually there are very established vertical market
suppliers, and they know their business and their customer needs well.
At a later stage, especially since we have a copyleft design, others might
become interested in doing improved derived versions, but I see this only
after several years.

So bottom line is that at least for Sharism Ltd., we will not jump into the
'OSM contributor device' right away, but we definitely have an eye on it,
and some things are coming together slowly that could get us to the point
where we can do such a device.
What do you think? Anybody else has any ideas?


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