JDPFu.com 2025

Had to reflash my Nokia N800 last week due to some sort of error. That fixed everything, however, it meant that I needed to reload all the applications – which is fine. It never hurts to reload the apps and wipe the trial’ed software off.

• Map Sources
• GPS Routes
• POI DBs
• Turn by Turn Voice Prompts

Maemo Mapper Sources

Anyway, the main app on this portable to me is Maemo Mapper a GPS tool. Previously, it was pre-configured to provide VE Maps, OpenStreet Maps, Yahoo! and Google Maps for street, satellite and hybrid maps. This time, only OpenStreet Maps was provided. I need to find how to add these other views.

• OpenStreetMap – Traditional “Mapnik” “http://tile.openstreetmap.org/%0d/%d/%d.png”
• Google Maps (street) “http://mt.google.com/vt/v=w2.95&x=%d&y=%d&zoom=%d”
  I hear that Google changes this from time to time.

Layers

Layers are maps which have transparency so they can overlay the map you are using and add additional information. For example to add Road and city names on Google Satellite or Google Terrain maps.

• Google Traffic “http://mt.google.com/mapstt?zoom=%0d&x=%d&y=%d”
• Google Labels “http://mt.google.com/mt?v=w2t.88&&z=%0d&x=%d&y=%d” (use with Google Satellite or Google Terrain for labels for cities, roads, etc., i.e. “Hybrid” maps.)

Download GPS Routes

There is good news. In my search to find those old map sources, I uncovered a fix to the routing by address. I never had this working before. It is really simple .

Maemo Mapper configuration as follows: Menu → Route → Download… and change the domain portion of the Source URL to http://gpx.geotags.com/ Leave the cgi-bin/gpx.cgi?saddr=%s&daddr=%s portion remains the same. It was good to see it work. Very nice.

POI Databases

Over the years, I’ve added a few Points Of Interest databases to the device. Chains of cheaper gasoline stations, my preferred fast food chains and Walmarts. You never know when you’ll need to buy something at a Walmart on a trip. I also have a list of over 1,000 waterfall locations. If I’m near a waterfall, it is nice to know it and stop when in the area. I need to build a list of hiking trailheads and parking areas.

Turn by Turn

flite is needed for a Synthesized Voice telling you to turn left. There are lots of dependencies that may not be easily achieved.

For about the last week, I’ve been in the Fort Collins, CO area for my niece’s wedding. That required about 6 hours total, but if I’m going all that way, I want to make it into a mini-vacation.

During the trip, I saw elk, bear, bear cub, rattle snake, rabbits, HUGE grasshoppers, millions of grasshoppers, gray squirrels, ground squirrels, and a few fish. A few interesting photos are below.

On Saturday, I went GeoCaching with an expert Geocacher (over 1000 caches found and logged). We went to a trail that I’ve hiked twice before, so I knew the terrain and was prepared for the effort required. At least I thought I was prepared. It turned out, I was not.

Equipment

I have a Nokia N800 that gets tethered via Bluetooth to a GoPass GPT800 Bluetooth GPS Receiver SiRF Star III. At the time of purchase, this was a highly regarded GPS receiver chip.

My sister had a hiking-specific GPS unit from Garman with a big antenna. I don’t know the exact model, but think it is a metal grey color with black and white screen. No color, since that uses too much energy.

My brother-in-law uses a few applications and scripts that he wrote to grab GPS point data for any geocaches near where we are planning to be. His scripts also grab hints and comments from other enthusiasts.

The Issues

So, we’re hiking on the path and we both have waypoints/POIs entered into our units marking the cache locations. I keep walking on the path, then my sister heads off into the brush. Not just a few feet off the path, but out of voice yelling range. We both have whistles, which is good hiking practice. My GPS was still telling me to continue on the path. She found it. I didn’t realize the cache locations wouldn’t be fairly near a trail. Since I’d already hiked these trails with my GPS tracking enabled, I had that prior track loaded into my map and could see approximately where the best place to take off into the bush would be.

GPS units appear to be designed for movement, somewhere around 10mph or faster seems ideal. I can’t walk that fast. When we stopped to get readings, mine jumped around a lot – hundreds of yards. Further, if the GPS signal gets lost due to trees, hills, whatever, then mine takes you back to a previous location as an initial guess. With tracking enabled, the map gets really busy with a pseudo-star pattern of lines.

Cockpit Error – i.e. user error ;)

On about the 3rd cache, I realized that the built-in compass for the GPS software wasn’t really working the way I thought. Fortunately, the same tool that my whistle is on has a compass, signal mirror, magnifying lens, thermometer and an LED flashlight . It is a really handy little plastic tool for hikers to have. I don’t mind that it is cheap, it does work. The compass was more than accurate enough for my needs, but sadly, the GPS location was still off. My sister kept making a beeline to the caches and found almost all of them in this area.

Final Result

I’ve decided that geocaching with my current setup isn’t fun. I get frustrated when technology doesn’t work as expected. To resolve the issue, wiping the original OS2008 included with the N800 will be needed. I’ve been unable to update the GPS mapping tool software since it was loaded due to some underlying libraries that couldn’t be updated too. A fresh OS install with the newer release will be good and get me out of Application Manager hell. Maemo 5, here I come. Then I’ll re-visit the same location and see whether the new software helps with the accuracy of the GPS. Knowing where some of the caches are located, will be helpful.

If this doesn’t work, perhaps it is time for a new bluetooth GPS receiver. The current receiver is really good for driving – seriously, so that $35 was well spent.

How to GPS Tag photos with your Nokia N800 and GPSbabel … The instructions here are not really specific to a Nokia N800, so other GPS units should use very similar steps. Only the GPSBabel part will probably change options based on your GPS device.

I’ve been taking my N800 and bluetooth GPS receiver on my hikes. Really just as a way to track approximate mileage. After doing that a few months, it seemed there had to be a way to put the GPS lat/lon into my photos. There is. A few other uses for GPS data, beyond the obvious:

1. Retain your track data
2. Estimate distance covered
3. GPS tag your photos
4. Share your track as a route for other hikers
5. Post a track on Google Maps for others – nice visualization with all the zoom and pan that you expect from google.
6. Mark the actual location of a landmark – waterfall, lookout point, or geocache

So far I’ve retained many of my tracks, but not been able to view them except on the N800. That’s useful, to a point. I’d really like to record them and create a database of visual tracks that is viewable on google maps for my friends to view. The real idea is to create a database of local hikes with trailheads, distances and difficulty ratings to help select future hikes.

Enter gpsbabel

Gpsbabel is a tool converts GPS data between many, many different devices and formats that runs on any platform – win32, unix, linux, N800. It supports conversion between … I guess about 50 different formats. My need is to convert N800/Maemo-Mapper GPX data into something GoogleMaps can use, KML. Originally, I thought gmaps supported GPX too, but that never worked well enough and had limited waypoint support. Yes, KML is the best answer for this.

Conversion steps for maemo-mapper gpx files into kml files that google-maps can display.

1. Get the GPX file off your N800 … somehow (scp, ftp, pull the memory card and copy the data, whatever)
2. Use gpsbabel to convert the file to KML.

   gpsbabel -t -i gpx -f “$1” -o kml,points=0 -F “$1.kml”

   points=0 option drops some data, so the resulting track isn’t exact.
3. Move the .KML file to a web server that googlemaps can access, anywhere really, on your desktop probably isn’t gonna work.
4. Have google maps display the data – a sample Laughing Falls, NC by fashioning a URL like the link here. Basically, you use http://maps.google.com/maps?q={full-URL-to-file.kml} The file can be waypoints, traces or routes as far as I can tell.

The result isn’t a nice track until you uncheck the Points on the resulting page. Also, I’ve tried to get gpsbabel to reduce the track to a radius around the importance locations, but that isn’t working. Loading gpsbabel was trivial on my Ubuntu laptop and desktop –

sudo apt-get install gpsbabel

, if memory serves.

No Google API key needed for this method either, which is nice.

Another helpful tool for geocaching and the N800 is gpsview. It connects to the GPS receiver and performs bearing math for you. It also helps calm the GPS data and average it out so you know where you are with a higher degree of accuracy after a few minutes, GPS data floats about 50 feet, IME. This tool is very helpful with some geocache hints. So, you have a location and need a bearing for the next cache location or you have a bearing and need a new lat/lon. gpsview does those calculations. I’d post a link, but I can’t find it now. Perhaps it was in the OS2008 depot and just loaded when I selected it.

Get out there and find some fun caches or just hike and know how close you are to roads and streams and where you’ve already been. There’s something fun about searching for a hidden location/waterfall, finding it, then taking an almost direct path back to your car.

Enter gpsPhoto.pl to tag your photos with GPS data

Tagging your photos with GPS coordinates:

gpsPhoto.pl —gpsfile HT-File.gpx \


	
Camera & GPS times match

            —timeoffset 0 \
	
Find closest GPS point (2 minutes)

            —maxtimediff 180 —dir ./ 

I came across a CSV list of waterfalls, converted it into KML and here’s the resulting googlemaps link. I know it is missing many water falls. I’ve been to some that are fairly large and they aren’t in the list. I have no idea how accurate any of these GPS points are either. YMMV.

Now that we have placed our GPS data into the photos, many of the photo hosting sites will display that either on a map or as part of the extra data. I’ve hacked together some GPS code for MyPhotoGallery that will link to google map locations for any photos that contain GPS data. Here’s an example of the EXIF data and Google Maps link that is added to every image displayed in the gallery.

Embedded EXIF data
Camera: SONY DSC-W55
Exposure: 1/160 sec.
Aperture: f/7.1
Focal length: 6.3 mm
ISO: 100
Flash: No
Date taken: Feb 21, 2009 at 3:17:21 PM
GPS: 34.135167,-84.704180

I’ve also hacked search into the perl and provided the search updates back to the original developer. He elected to remove search from his code many years ago. If you are interested in my changes photo gallery, they are hacks, let me know. If there is enough interest, I’ll post them for all.