An It-slave in the digital saltmine

Background

I have a need of GPS tag my digital photos. Unfortunatly a GPS device to my camera costs approx 230 Eur. In my humble opinion I think that is way of, especially considering that with some software in the camera any standard USB GPS reciever would do the job. They cost approx 40 Eur.

I have an Android phone where there is tons of apps that could create a GPS log whenever I want to, however it drains the battery in just a couple of hours. I want to track my routes at least a whole day without the need to charge.

The solution is to buy a GPS logger and after some research I found Ventus GPS Route Logger G730, and it looked like it would work with Linux.

This article will describe my experience making the G730 Ventus GPS Route Logger and Linux.

Using skytraq

According to webpages skytraq can be used to create GPX tracks from the G730 Logger.

Unfortunatly the skytraq software are not in the Ubuntu repos so I had to download and install it manually. It is downloadable from  http://code.google.com/p/skytraq-datalogger/

It is out of the scope for this article how to compile and fullfill the requirements needs.

When the GPS Logger is attached the following will show up in /var/log/messages:

Jan 15 14:13:08 it-slav kernel: [21689.101101] usb 6-2: new full speed USB device using uhci_hcd and address 3
Jan 15 14:13:09 it-slav kernel: [21689.316181] usb 6-2: configuration #1 chosen from 1 choice
Jan 15 14:13:09 it-slav kernel: [21689.319138] pl2303 6-2:1.0: pl2303 converter detected
Jan 15 14:13:09 it-slav kernel: [21689.332192] usb 6-2: pl2303 converter now attached to ttyUSB0

So now we can communicate with the GPS Logger:

peter@it-slav:~/dl/skytraq/skytraq-datalogger-0.5-1$ ./skytraq-datalogger --info
kernel version: 1.4.8 -- ODM version: 1.8.22 -- revision: 2008-10-23
log_wr_ptr:      28626
total sectors:   510
sectors left:    506
max time:        3600 s
min time:        1 s
max distance:    1000 m
min distance:    0 m
max speed:       1000 km/h
min speed:       0 km/h
datalog enable:  1
log fifo mode:   1
AGPS enabled:    0
AGPS data left:  none
baud-rate:       38400 bps

Get the gpx file:

./skytraq-datalogger --dump >20110310.gpx

And now a gpx file named 20110310.gpx is created.

Setup

There is a possibility to conifigure the behvior of the GPS logger with skytraq, however it is possible to configure more parameters in the Ventus G730 so to fully configure I had to install the windows software that come with the logger.

The configuration is rather strange, there is a possibilty to log per time, over a certain speed and distance for the following:

• General
• Walking
• Car
• Bicycle

How the device knows what type of vehicle I use for traveling and if the General settings override the others is undocumented.

Problems

Most of the time when trying to communicate with the logger it gives this message:

peter@it-slav:~/dl/skytraq/skytraq-datalogger-0.5-1$ ./skytraq-datalogger --info
No response from datalogger.

And after a few seconds it works again. Sometimes unplugging the device and connect it again helps. The behavior is very stochastic and some patience will help:)

The logger can be used as a GPS recever and the output is in standard NMEA format that GPSd understand. So if you want to use it together with your favorite GPS software it works. However my experience is that if you want to dump the output from the G730 Logger the GPS output must be turned of:

./skytraq-datalogger --set-output-off

Suggestion

I suggest that Ventus should open the specification howto communicat with the device so third part software could use the device. To hide that type of information do not provide any advantage, rather the opposite.

I wrote an email to them and the correspondence can be seen below. I hope this blog post will make Ventus change their mind.

–cut–

-------- Original Message --------
Subject: Sv: Ventus g730
Date: Mon, 3 Jan 2011 13:25:49 +0800
From: <support@ventusdesign.com>
To: Peter Andersson <peter@it-slav.net>
CC: Ventus <info@ventusdesign.com>

> Hi
>
> I have just bought a Ventus g730 GPS Logger and I have some feedback.
> Before buying the device I made sure that it fullfilled my requriements:
> -Works with linux
> (http://www.petrilopia.net/wordpress/hardware/ventus-gps-route-logger-g730-linux/)
> -Create gpx files
> -Battery that last at least 12 hours
>
> Unfortunately you have have taken a strange decision and do not support
> Linux. However according to several forums the G730 is compatible with
> http://code.google.com/p/skytraq-datalogger/
> After fiddling with the device I found that the skytraq-datalogger
> sometimes works and sometimes does not. And I probably will return the
> device to the store if I cannot get it to work better with an open and
> free operating system.
>
> My recommendations to you are:
> 1-Provide an open specification how to access the data in the device
> 2-Modify the http://code.google.com/p/skytraq-datalogger/ software so it
> works with G730 and provide the code change to the team behind
> skytraq-datalogger, and also provide the software on you website.
>
> By following these simple steps (especially #1) you will sell a-lot of
> more devices to the people that prefer open and freedom.
>
> Best regards
> Peter Andersson
> peter@it-slav.net
 

2 Responses to “Using Ventus GPS Route Logger G730 in Linux”

1. Ventus Support Says:
   September 2nd, 2011 at 8:33 am

   Hi Peter

   Ventus has a significant investment in intellectual property and product development which we strongly protect

   If we release these information we will help our competitors copying our device.

   Hope for your understanding.

   Kind regards

   Ventus Design
   Jesper Batting

2. peter Says:
   September 2nd, 2011 at 9:15 am

   Classic FUD arguments.

   I do not ask for open up the firmware or provide the design, just how to communicate with the device. It is a big difference.
   I doubt that the communication and configuration protocol is intellectual property, especially when it almost works by using software made for another device and vendor.

   I’m convinced that if you provide the specs howto configure and communicate with the device you will sell more and make more money.

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