Holux M-241 GPS Logger
Posted: Mon Aug 18, 2008 7:27 pm
For many years I have wanted an easy way to tell where I took a photo.
This was most noticeable after returning from a three month trip across Japan, the then USSR, Finland, Norway, Sweden, Germany, and Holland. In those days I was using print film and ,despite keeping a journal, to this day I am not sure even what country some of the scenes were in, let alone their actual location.
When I saw that the D200 had as an option a device for Geotagging photos, I thought that this was for me. Then I discovered that the option was a thousand dollars or so, and you still needed to get a compatible GPS device. Clumsy AND expensive. Grr. I did have a GPS, but as an early adopter, it was a very basic model. I was unsure whether it could all work together. Certainly, I was not about to risk $1000 on the bet.
Then I saw comments here and elsewhere that it was possible to geotag your photos without the expensive Nikon add on. Interested? Sure was. I looked at my GPS, a venerable Garmin 12XL.
It was capable of connecting to a computer via a serial cable, provided you made the connector, and found the software. Then it was capable of only about 1000 waypoints. Still not a viable option. Damn.
Then I saw Stubbsy's unit on the Ferry Hop. Nice and small. “Let's look into this” I thought.
See http://www.dslrusers.com/viewtopic.php?f=17&t=31540 for his comments.
On to the Web. There are lots of these units. All have slightly different feature sets. Some are waterproof. Some record enormous amounts of information. Some have bluetooth. Some USB.
Some run for 32+ hours on a Li-Ion battery. Some run on AAAs.
I settled on the Holux M-241
Price: I paid USD69.00 + USD28P&H With the Pacific Peso falling, this came to AUD114 out of my account
Hardware
Size of the unit is good. It is about 32x30x75 mm. This makes it about the diameter of a film canister and 1½ times the height. It comes with a lanyard, so I wear it around my neck. Convenient, and always there when I take that photo.
Not waterproof. This could be a worry. If I was using it on a boat, I would pack it in a waterproof canister.
Power: A single AA battery. Both Alkaline and NiMh are specifically stated as acceptable. As I am generally carrying a few of these around anyway, this is good for me. It can also be powered by the USB port. This opens up all sorts of aftermarket battery options.
Battery life: It claims 12 hours on Alkaline batteries. I have certainly got > 8 hours from a NiMh cell, but as the manual warns that switching off without stopping the log function can corrupt the unit, I am reluctant to perform the obvious test. Sadly, using the USB power option does not charge the battery.
Precision: It gives a location precise to 0.01” of lat/lon. This is something less than a metre; but see accuracy.
Log: The documentation claims over 130,000 log points. The unit claims 131033 log points You can record by time or distance. Time gives allows for an entry every 1, 5, 10, 15, 30, 60 or 120 seconds. So depending on your setting, you can record for up to six months without filling the log. I will be going to NZ for a week next month. I will set it to record every 5 seconds. That will give me 7.5 days of records. Just enough. Distance setting allows for 50…1000 metres. The latter would allow you to track your progress around the world.
Datum: Not specified (Have I ranted about the poor documentation yet?) I think it is WGS84 as it seems a good match with Google Earth. This is really only important if you have a need to compare the unit’s output with paper maps. For example, there is about a 200 metre discrepancy between WGS84 and AGD66 which is what most of my CMA maps are based on.
Connectivity: Bluetooth and USB. You need a driver (supplied (Win)) for USB. I didn’t succeed in connecting via Bluetooth (probably my fault, but see documentation)
Display: The only data logger I found that has one. Small, but clear. I like it. If you break down in the rain somewhere on the Hume Highway, you can simply call up the NRMA and quote the Lat/Lon where you are, all without getting out of your car. (Yes I have done this with my Garmin) On a more frequently useful basis, the display will indicate if you have a satellite lock or not, though it doesn’t indicate how good the lock is.
Things you can do with the display:
...Know that the GPS has a lock
...Know where you are (Lat/Lon)
...Know how high you are (Alt) in metres or feet
...Know what time it is
...Know how far you are from a set point (either along a route you have travelled or in a straight line)
...Know how fast you are going (km/h or mph)
...Alter all your setup options. e.g. Record by time or distance & set the interval.
...Start & stop logging. Separate Start/Stop for Distance and Location.
...Clear all track points (Quicker & easier than doing it with the S/W)
Accuracy: Like all GPS units, this is dependent on the number and position of the satellites the unit can see at the time. I would like it if the unit gave an indication of position error on screen, or better, a means of averaging a position. See my Garmin for reference. It is not as precise, but it indicates that the position is +- 4.3 meters. This can be good to know.
Speaking of the Garmin, it is not uncommon for the fix to have an estimated position error of 30m. I recall one case when I was walking along. The position suddenly jumped about 3,000km, stayed there for several minutes, then jumped back. I can only assume a satellite went belly up. As position is satellite dependent, I would expect the Holux to be the same, but there is no way of finding out. I performed a test by setting the unit out in clear view of the sky, and left it logging every 5 seconds for about 3½ hours. The recorded location moved about within about an 8 metre circle. The unit itself did not move. Certainly good enough for saying “I took that holiday snap overlooking the lake at Wanaka” (my intended use), but not, perhaps, for recording where you found that rare and extremely endangered native orchid.
Other stuff
Manual. In a word: Woeful. Fortunately the unit is fairly self evident in use. The menu structure in the Setup section takes a little getting used to, but otherwise it is clear sailing. There is a more comprehensive (and clearer) manual on the accompanying CD-ROM
Device driver: it works (not sure if I used the one off the CD or one Windows found on the web.) No documented drivers for Mac/Linux
Software: Like the manual. Very poor. It does the job but…
It needs its own software to connect to a PC, and a MAC option is not available (or at least, not documented)
You need to delve into your computer’s backend and work out what COM port has been allocated to the device. The software has an “AutoDetect” button that should do this for you, but I tried it twice. First time I waited about 2 minutes, then used the manual connect button. The program crashed. The second time I waited over 10 minutes before giving up and using the manual connect button. This time it did not crash.
The software does not remember the COM port (or any other setting for that matter) between uses, so every time you connect; you need to change the COM port to the correct one.
You need to download the track log to you computer, setting the destination EVERY time. The default location is “My Computer” so you can’t even use the default & worry about it later. This download creates two files: a trl file and a kml file. The kml file can be used for loading into Google Earth, but the trl file is a binary and needs further processing before it can be used.
Once you have downloaded these two files, you need to process them further. This is another step. Again you need to specify source and destination EVERY time. Also, the KML file is not suitable for use by GeoSetter (and probably other Geotagging software). You need to create a GPX file in the processing step.
The software claims to be able to geotag jpg (not RAW) files directly, but frankly, having struggled to get this far, I can’t be bothered. I did try once with no success, but moved on to GeoSetter fairly quickly.
Conclusions
I like the actual unit, but I am looking into ways to avoid using the supplied software. I have already settled on freeware Geosetter http://www.geosetter.de/en/. Its documentation is also poor (almost as bad as the Holux doco!), but I am getting there, and at least that documentation is value for money. I am also looking into ways of avoiding the Holux software to download too. GPSBabel (http://www.gpsbabel.org/)looks promising, but I haven’t worked out how to drive it yet.
A final note. This is relevant to your software, rather than the unit itself. It is important to have your camera and GPS Logger to be synchronised to the second, or better, if you can do it. My camera was about 21 Sec different from the GPS as a result, the software placed the photo where the Blue/Orange pin is. Once I worked out how to get GeoSetter to allow for this discrepancy, it placed the photo where the Red pin is (on the bridge). This is pretty well spot on. NB that GeoSetter interpolated between two track points to achieve this. Mind you I was travelling at about 110Km/h at the time.
This was most noticeable after returning from a three month trip across Japan, the then USSR, Finland, Norway, Sweden, Germany, and Holland. In those days I was using print film and ,despite keeping a journal, to this day I am not sure even what country some of the scenes were in, let alone their actual location.
When I saw that the D200 had as an option a device for Geotagging photos, I thought that this was for me. Then I discovered that the option was a thousand dollars or so, and you still needed to get a compatible GPS device. Clumsy AND expensive. Grr. I did have a GPS, but as an early adopter, it was a very basic model. I was unsure whether it could all work together. Certainly, I was not about to risk $1000 on the bet.
Then I saw comments here and elsewhere that it was possible to geotag your photos without the expensive Nikon add on. Interested? Sure was. I looked at my GPS, a venerable Garmin 12XL.
It was capable of connecting to a computer via a serial cable, provided you made the connector, and found the software. Then it was capable of only about 1000 waypoints. Still not a viable option. Damn.
Then I saw Stubbsy's unit on the Ferry Hop. Nice and small. “Let's look into this” I thought.
See http://www.dslrusers.com/viewtopic.php?f=17&t=31540 for his comments.
On to the Web. There are lots of these units. All have slightly different feature sets. Some are waterproof. Some record enormous amounts of information. Some have bluetooth. Some USB.
Some run for 32+ hours on a Li-Ion battery. Some run on AAAs.
I settled on the Holux M-241
Price: I paid USD69.00 + USD28P&H With the Pacific Peso falling, this came to AUD114 out of my account
Hardware
Size of the unit is good. It is about 32x30x75 mm. This makes it about the diameter of a film canister and 1½ times the height. It comes with a lanyard, so I wear it around my neck. Convenient, and always there when I take that photo.
Not waterproof. This could be a worry. If I was using it on a boat, I would pack it in a waterproof canister.
Power: A single AA battery. Both Alkaline and NiMh are specifically stated as acceptable. As I am generally carrying a few of these around anyway, this is good for me. It can also be powered by the USB port. This opens up all sorts of aftermarket battery options.
Battery life: It claims 12 hours on Alkaline batteries. I have certainly got > 8 hours from a NiMh cell, but as the manual warns that switching off without stopping the log function can corrupt the unit, I am reluctant to perform the obvious test. Sadly, using the USB power option does not charge the battery.
Precision: It gives a location precise to 0.01” of lat/lon. This is something less than a metre; but see accuracy.
Log: The documentation claims over 130,000 log points. The unit claims 131033 log points You can record by time or distance. Time gives allows for an entry every 1, 5, 10, 15, 30, 60 or 120 seconds. So depending on your setting, you can record for up to six months without filling the log. I will be going to NZ for a week next month. I will set it to record every 5 seconds. That will give me 7.5 days of records. Just enough. Distance setting allows for 50…1000 metres. The latter would allow you to track your progress around the world.
Datum: Not specified (Have I ranted about the poor documentation yet?) I think it is WGS84 as it seems a good match with Google Earth. This is really only important if you have a need to compare the unit’s output with paper maps. For example, there is about a 200 metre discrepancy between WGS84 and AGD66 which is what most of my CMA maps are based on.
Connectivity: Bluetooth and USB. You need a driver (supplied (Win)) for USB. I didn’t succeed in connecting via Bluetooth (probably my fault, but see documentation)
Display: The only data logger I found that has one. Small, but clear. I like it. If you break down in the rain somewhere on the Hume Highway, you can simply call up the NRMA and quote the Lat/Lon where you are, all without getting out of your car. (Yes I have done this with my Garmin) On a more frequently useful basis, the display will indicate if you have a satellite lock or not, though it doesn’t indicate how good the lock is.
Things you can do with the display:
...Know that the GPS has a lock
...Know where you are (Lat/Lon)
...Know how high you are (Alt) in metres or feet
...Know what time it is
...Know how far you are from a set point (either along a route you have travelled or in a straight line)
...Know how fast you are going (km/h or mph)
...Alter all your setup options. e.g. Record by time or distance & set the interval.
...Start & stop logging. Separate Start/Stop for Distance and Location.
...Clear all track points (Quicker & easier than doing it with the S/W)
Accuracy: Like all GPS units, this is dependent on the number and position of the satellites the unit can see at the time. I would like it if the unit gave an indication of position error on screen, or better, a means of averaging a position. See my Garmin for reference. It is not as precise, but it indicates that the position is +- 4.3 meters. This can be good to know.
Speaking of the Garmin, it is not uncommon for the fix to have an estimated position error of 30m. I recall one case when I was walking along. The position suddenly jumped about 3,000km, stayed there for several minutes, then jumped back. I can only assume a satellite went belly up. As position is satellite dependent, I would expect the Holux to be the same, but there is no way of finding out. I performed a test by setting the unit out in clear view of the sky, and left it logging every 5 seconds for about 3½ hours. The recorded location moved about within about an 8 metre circle. The unit itself did not move. Certainly good enough for saying “I took that holiday snap overlooking the lake at Wanaka” (my intended use), but not, perhaps, for recording where you found that rare and extremely endangered native orchid.
Other stuff
Manual. In a word: Woeful. Fortunately the unit is fairly self evident in use. The menu structure in the Setup section takes a little getting used to, but otherwise it is clear sailing. There is a more comprehensive (and clearer) manual on the accompanying CD-ROM
Device driver: it works (not sure if I used the one off the CD or one Windows found on the web.) No documented drivers for Mac/Linux
Software: Like the manual. Very poor. It does the job but…
It needs its own software to connect to a PC, and a MAC option is not available (or at least, not documented)
You need to delve into your computer’s backend and work out what COM port has been allocated to the device. The software has an “AutoDetect” button that should do this for you, but I tried it twice. First time I waited about 2 minutes, then used the manual connect button. The program crashed. The second time I waited over 10 minutes before giving up and using the manual connect button. This time it did not crash.
The software does not remember the COM port (or any other setting for that matter) between uses, so every time you connect; you need to change the COM port to the correct one.
You need to download the track log to you computer, setting the destination EVERY time. The default location is “My Computer” so you can’t even use the default & worry about it later. This download creates two files: a trl file and a kml file. The kml file can be used for loading into Google Earth, but the trl file is a binary and needs further processing before it can be used.
Once you have downloaded these two files, you need to process them further. This is another step. Again you need to specify source and destination EVERY time. Also, the KML file is not suitable for use by GeoSetter (and probably other Geotagging software). You need to create a GPX file in the processing step.
The software claims to be able to geotag jpg (not RAW) files directly, but frankly, having struggled to get this far, I can’t be bothered. I did try once with no success, but moved on to GeoSetter fairly quickly.
Conclusions
I like the actual unit, but I am looking into ways to avoid using the supplied software. I have already settled on freeware Geosetter http://www.geosetter.de/en/. Its documentation is also poor (almost as bad as the Holux doco!), but I am getting there, and at least that documentation is value for money. I am also looking into ways of avoiding the Holux software to download too. GPSBabel (http://www.gpsbabel.org/)looks promising, but I haven’t worked out how to drive it yet.
A final note. This is relevant to your software, rather than the unit itself. It is important to have your camera and GPS Logger to be synchronised to the second, or better, if you can do it. My camera was about 21 Sec different from the GPS as a result, the software placed the photo where the Blue/Orange pin is. Once I worked out how to get GeoSetter to allow for this discrepancy, it placed the photo where the Red pin is (on the bridge). This is pretty well spot on. NB that GeoSetter interpolated between two track points to achieve this. Mind you I was travelling at about 110Km/h at the time.