[FOSS-GPS] Participants wanted for Nokia's PUSH competition

Thu Sep 24 12:10:59 EDT 2009

Only permanent reference stations need to "auto power".  If you're setting
up a temporary reference station, then you could use the same hardware as
the rover.

OEM receivers usually have a serial port which can feed directly to a
bluetooth module. You'd have to set up power, probably using rechargeable
batteries with a super capacitor to keep things going while you change
batteries.  You'd also want to set up an external battery pack for the phone
so you can do a full day's session. Everything needs to be weatherproof, and
there are bonus points if it is playfully attractive.

So here's one hardware possibility:

    OEM receiver with TTL serial output  (AC12, LEA-5T, or ???)

    Bluetooth module (bluesmirf)

    Super capacitor to keep things going while batteries are replaced

    External antenna  (Trimble compact dome or ??)

5V Power pack, one for GPS and one for phone  (purchase if possible)

    Rechargable lithium batteries in accessible battery holder (18640?)

    voltage converter/regulator, etc

    Low battery indicator

Rethinking the major components:

.         The reference station would be tripod mounted, generate RTCM 3.1
and distribute data via NTRIP. It could function as either an NTRIP server
(sending data to an external caster) or it could function as a small NTRIP
caster.

.         The rover would be backpack mounted (a survey pole isn't needed
for 1/2 meter accuracy), and the N900 would do GIS acquisition as well as
positioning. 

.         The GPS differencing software would simulate a GPS producing NMEA
messages on a pseudo-serial port. The software would generate successively
more accurate positions whenever the rover is standing still.

.         Most GIS acquisition software can accept NMEA messages. Hopefully
we could use something "off the shelf" like CyberTracker.

It isn't necessary to use RTCM 3.1 or NTRIP, but keeping to these standards
allows other reference stations or rovers to make use of the data.

  - John

-----Original Message-----
From: foss-gps-bounces at lists.osgeo.org
[mailto:foss-gps-bounces at lists.osgeo.org] On Behalf Of Joseph Reeves
Sent: Tuesday, September 22, 2009 5:07 AM
To: Open Source GPS-related discussion and support
Subject: Re: [FOSS-GPS] Participants wanted for Nokia's PUSH competition

Hi John,

>Some possible simplifications:

> O The base station could provide ntrip directly to the N900 rover which

>would do the processing.

> O The webservice could be implemented on the base station, eliminating the

>need for ntrip.

> O The repository could be dropped, allowing only "recent" measurements to

>be processed.

These were all the sorts of things I was thinking - using a base

station running on a P900 to a local network of connected devices.

> How do you plan to connect GPS receivers to the N900? The USB plug appears

> to be "device" instead of master.

I was thinking of using the phone's internal antenna. Would this be

suitable? For use on a detail pole, etc, we'd have to hack an external

antenna to it, or hope that there's a test location on a PCB that

could have an external antenna attached to.

> Bluetooth is nice for the rover, but it is

> a pain for the reference station.

Yes, this is something that will take some thought. Even in the Speak

and Spell example provided by Nokia they use bluetooth to communicate

with an arduino just inches away :-/

> Also, an N900 reference station needs to

> "auto power" so it can operate unattended.

It could function as a base station only when connected to by a rover?

Am sure there must be some software trickery that could be used for

that.

Cheers, Joseph

2009/9/22 John Morris <john at coyotebush.net>:

> I'd be interested ... I was just getting ready to do something similar.

> 

> I've been thinking in terms of GIS data collection. The components would

> include:

>  O GIS collection software on the phone, (possibly a modified
CyberTracker)

>  O A webservice for processing raw GPS data, giving "backpack" quality

> positions.

>  O A Repository of base station data, allowing postprocessing as well as

> current processing.

>  O An ntrip reference station (based on AC12 or LEA-4(5)T)

> 

> As a simplification, I was going to do 20-30 second static positions based

> on pseudorange.  I originally choose a webservice to save both bandwidth
and

> handset compute power. Phase based kinematic processing is the "holy
grail",

> but it probably couldn't be implemented in a short time frame. Walk, then

> run.

> 

> I was going to use a Linksys nslu2 "slug" for the ntrip reference station.

> I'd use a commercial "rent a web" server for the repository and
webservice.

> It should be possible to move everything onto an N900 for a "Nokia-only"

> solution.

> 

> Some possible simplifications:

>  O The base station could provide ntrip directly to the N900 rover which

> would do the processing.

>  O The webservice could be implemented on the base station, eliminating
the

> need for ntrip.

>  O The repository could be dropped, allowing only "recent" measurements to

> be processed.

> 

> How do you plan to connect GPS receivers to the N900? The USB plug appears

> to be "device" instead of master. Bluetooth is nice for the rover, but it
is

> a pain for the reference station. Also, an N900 reference station needs to

> "auto power" so it can operate unattended.

> 

>  - John Morris

> 

> PS. I have assorted hardware, including an nslu2, a pair of AC12's, an

> LEA-4t, and a collection of compact dome antennas. The GPS receivers are

> wired for USB.

> 

> 

> 

> -----Original Message-----

> From: foss-gps-bounces at lists.osgeo.org

> [mailto:foss-gps-bounces at lists.osgeo.org] On Behalf Of Joseph Reeves

> Sent: Monday, September 21, 2009 5:03 AM

> To: Open Source GPS-related discussion and support

> Subject: [FOSS-GPS] Participants wanted for Nokia's PUSH competition

> 

> Dear all,

> 

> Nokia is running a competition to hack / publicise their upcoming N900

> smartphone; they say:

> 

> "We want you to come up with ideas to hack the N900. A panel of expert

> judges will pick the most impressive ideas. We'll support you to

> create them and then take the final creations on a world tour."

> 

> There's more on the website here:

> http://blogs.nokia.com/pushn900/index.php/what-is-push/

> 

> I'd like to hear from people who would be interested in contributing

> towards a D-GPS project based upon the Nokia phone; I'll stand as

> project lead and start work on the 1000 word description if there's

> enough interest. I propose the development of a D-GPS framework to

> enable high accuracy GPS position recording within a network of

> locally connected N900s and to provide two implementations of this

> technology; a hardware hack to provide the phone with a high

> sensitivity antenna and detail pole for survey grade recording and a

> second, standard hardware implementation, to enable precise location

> and messaging within an urban environment.

> 

> The deadline for proposals is October 11th, so if anyone's interested

> we better start working soon.

> 

> Cheers, Joseph

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