Tuesday, November 02, 2010

Dual XGPS300, GPS and Cradle for iPod Touch Part II

Now that I have had the chance to work with the Dual GPS Cradle for about a month, I have learned several important lessons and uses.

The most important functions and constraints are:

  1. It works as a GPS while I still can use my Touch to play music on it. You need to start playing the music prior to starting a gps application, but the music will continue to play in background while the cradle makes the Touch act like a GPS.
  2. The GPS does supply data to applications that are written for the iPhone GPS chip. I have used the GPS function with several different applications wrote for the iPhone and they all seem to work very well. The GPS of the cradle is very sensitive and generally work within a single floor building.
  3. When I have used the iPod Touch with my wireless internet card it has done a nice job of loading maps quickly as I am moving, I have used it with Google Earth as I was driving, once my speed increases beyond about 30 miles per hour, the map had trouble displaying information quickly enough to keep me on the map. But when I was walking across the Purdue campus (where my daughter attends) to attend a football game it did a very good job of keeping my position visible on the screen. The one problem is that the Touch will go into sleep mode. This does not occur when utilizing the GPS software that comes with the Cradle; it does not go into sleep mode.
  4. The GPS switch on the back of the cradle is important. If you leave the switch in the GPS position the cradle battery will discharge relatively rapidly and when the cradle battery is discharged the GPS will not function. Therefore, it is important when using in the field to move the switch to the off position when not using as a GPS.
  5. It does a good job with ESRI application as well as other free apps. I have at this time not purchased any applications, but have downloaded several free applications.
  6. I used the Cradle GPS and compared it to my notebook GPS on a recent trip to Washington DC and would say they compared very similar. They both indicated my turns, distances and speed. While the routes varied slightly, they both gave the same speeds and distance to turns. The Cradle GPS also brought up graphics (on some exits) of what the exit looked like, I just wish it would have brought the graph up a little sooner (less than a tenth of a mile) and had a very limited set of exits that it displayed.

Thursday, October 07, 2010

Dual XGPS300, GPS and Cradle for iPod Touch

This article will discuss the usage of a Dual XGPS300 Cradle (retails for around $200) to convert an iPod Touch into a GPS. The cradle contains a battery which can be used to charge the iPod Touch, a GPS receiver, as well as windshield mount and car charger. When the GPS is plugged into the cradle initially it will download two software applications to utilize the GPS functions (if connected to broadband). One application shows only your current coordinates (GPS Cradle) to thousandth of a degree while the other shows your position on a map (NavAtlas). When the software is running it turns off the sleep mode of your iPod Touch so it displays the map continuously. The GPS functions also work with typical iPod Touch function such as touch screen, zooming and automatic screen rotation. The cradle is a true GPS not using any type WiFi or phone method to determine position instead it use the GPS constellation of satellites.

According to Dual (http://www.gpscradle.dualav/com/how) that any program that request GPS functions will work the cradle. Apps designed for the iPhone should work successfully with the cradle and while the apps that are free with the Cradle have limitations it has links to numerous apps to use, some are free and others have a cost associated with them. This includes geocaching ($7.99 - $9.99) Hiking ($4.99 - $7.99), Biking (free - $2.99), food (free), golf (free - $9.99). A future post will discuss these other software.

The cradle makes the iPod Touch function like most commercial car GPS units. It has a feature which assumes that it is in a car and you should be on a road, so once you have left the road it still tries to keep you on the road for several 100 feet. For example as I was driving across the parking lot it wanted to keep me on the road initially until I got several hundred feet away from the road. Therefore, it does not have as much function as a GPS that is made for trails or hunting because of this limitation within the software. But as a car GPS it has very good maps with lots of Points of Interest (POI) and you can control which ones are displayed. You can also route trips using the features built into the software, which will display turns, distances and time to destination. It will give verbal information either through the external speakers of the cradle or by connecting into your car radio auxiliary jack. When connect to the car radio, the radio must be in the auxiliary position to hear the voice commands. The trip routing was very good and compared to other GPS's that I use with computer software. You do have the limitation of the size of the iPod Touch screen.

A feature that other car GPS cannot do is play music, you can play music on the iPod Touch while using the GPS functions and both worked just as they did individually. Since all the maps are loaded on the Touch when the app is installed it takes up about 35% of my 8GB Touch. I do this same operation (playing music and GPS) with my Netbook and USB GPS using Delorme Street Maps and car power inverter. While the map is smaller than with my Netbook (similar size to most car GPS units), it is touch sensitive and is mounted directly on my windshield something I cannot do with my Netbook.

The cradle also comes with a windshield mount that stayed fixed to my windshield over some fairly bumpy roads; the mount contains a holder for the iPod Touch GPS with clip to make sure it keeps good connections as well as a patch cable to connect to the car radio and a power connector for the car's auxiliary power connector.

The only real disadvantage of this GPS is that it does not function well as a trail GPS with the software that comes with it. The cost is reasonable if you already have an iPod Touch, but if you are purchasing the iPod and cradle only for GPS usage it is expensive.

Wednesday, May 12, 2010

New Presentations

Three new presentations have been prepared for the KCTCS New Horizon Conference.

Thursday, March 11, 2010

Cities Moved in the Chile Earthquake

An interesting fact due in large part to GPS technology is the determination that several cities moved during the recent 8.8 magnitude earthquake in Chile. The city of Concepcion, Chile near the epicenter of the earthquake has moved at least 10 feet. The capital of Chile, Santiago, moved about 11 inches. Both of these movements were to the west. Therefore, the maps on a handheld GPS might be inaccurate. To learn more about this go to: http://www.msnbc.msn.com/id/35780643/ns/technology_and_science-science/ and for a dynamic map of the area visit our map located at

Thursday, January 28, 2010

Microsoft Live Sync


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How many times have you left home only to realize that data that you needed was back on your home computer and you cannot access it directly or you want to share a file with an out of town colleague only to realize the file size is larger than your email limitations or that you and your colleague both updated the file and the files are not synchronized.

Potential solutions might be found in cloud computing by the use of online application that stores information in the 'cloud'. For example if the application software is online such as Google Documents then you can write your document online and share it with colleagues or access it yourself through the web on any computer. But if the files are your not typical applications like spreadsheets, word processing files, etc. then the cloud computing might not solve the problem.

For our application we will be looking at geospatial files (geodatabase) that will be generated by one team of researchers in Illinois and another team in Kentucky that uses a Flex map server located in Kentucky. So when the geodatabase is edited by Illinois team and saved it will automatically port to the Flex map server and will be displayed when the map is accessed via of the Internet. This collaboration should be seamless to the user and the researcher, since each team will be updating files in local folders, but will be synchronized in the background. The solution that the team will utilize is Microsoft Live Sync. http://sync.live.com

The test that we have run has three different users accessing the same file folder that contained over 2000 files and multiple gigs of information, one of the users has three different computers connected to the sync folder; one on an on campus computer a pc, another on campus computer which is a mac, and the third is an off campus computer. Therefore, five different computers have a common synchronization with one folder; any changes made to any of the five local folders will result in a change on all five computers. One of the computers used in the test has the folder on an external harddrive. The Live Sync will also work on single users personal folded, in addition once the sync program is running on the remote computer of one user, it can be browsed and files accessed via the web.

What happens if multiple people access the same folder? Since the folders and files are saved on each local computer and there is no interconnection between the files, there is no locking of the file, as would occur on a single computer or a server. Therefore, if two people open the same file at the same time, they both can modify the file, when the file is saved a synchronization will occur on all computers, so the first saved file will be synchronized and then when the second file is saved it will not have the information from the first user since that file was open when the save occurred. So when the second user saves the file, it will overwrite the work of the first user and those edits will be lost on all computers once the synchronization occurs. There are server solutions that will keep the files synchronized or lock other user out of the files, but this solution is free, easy to install and ports through firewalls.

Microsoft Live Sync seems to be a powerful free tool for three uses, synchronization of personal files, sharing files among colleagues and the ability to browser your own personal remote computer passing through firewalls. The limitations are the ability to do simultaneous editing of common files. It does not appear to have any size limitations on the amount of data that will be passed between individuals. The initial synchronization does take some time depending on the size of the file folder.

Monday, November 02, 2009


A friend recently made me aware of the following application which might be of use to you in your work. It is called WolframAlpha and can be located at http://www.wolframalpha.com/.

It is a computational engine that appears to be very powerful. It uses the mathematic form. The image below is one of their examples.
I typed in fall 100 m and I got this:
Ss I explore this engine in more details I will write additional information. This is a partial list of what claims it can do:

Friday, September 18, 2009

GPS Workshop

A half day GPS workshop is being help on September 18th on the Southwest Campus of Jefferson and on September 25th on the Downtown Campus of Jefferson. The material for the workshop is posted at http://techcenter.jefferson.kctcs.edu/RS/topics/GPS/Pages/default.aspx which is part of an online remote sensing course and the slides are posted at http://techcenter.jefferson.kctcs.edu/presentation/Vince/091809/Pages/default.aspx. Additional information about the workshop can be obtained by contacting me directly.