User Review: Droid vs Garmin for Bicycle Navigation

My father is a geek like me, though has been budget-conscious for my whole life. A few months ago, he started asking me a wide variety of questions of different types of devices he could use to fill his various needs, including bicycling and genealogical research in an area with highly spotty coverage. Numerous email exchanges later, we both decided on getting a Motorola Droid. He sent over this commentary on how it works for bicycling, partially to help another person in his device decision. I find the analysis fascinating. I hope you do, too.

I've experimented with using the various GPS Receiver functions of my new Motorola Droid toy. In short the Droid functions about as well as my Garmin eTrex in determining location but the Droid has limited navigation functionality when it is outside 3G coverage. Additionally the battery drain rate is high.

It appears that the Droid uses GPS satellites to determine its location for navigation type functions although it uses cell tower and WiFi data in conjunction with some apps.

Satellite acquisition and initial location determination

When I first turn on my Garmin it takes a couple of minutes to acquire satellites and calculate the current location. The unit "knows" where it was when it was turned off and has a catalog of satellites that it should see but it takes time to acquire those satellites and gather enough information to calculate location.

At home when I turn on Google Maps on the Droid it first shows a location based on cell tower data (I'm away from any known WiFi hotspots). It then quickly (less than 30 sec) zeros in on my house location. The impression is that the Maps App is much quicker in getting to the initial location than the eTrex. Ed. note: This is most likely due to the cell tower assistance.

I turned on the satellite view mode on Google Maps which shows aerial photography of my area. The blue dot showing my calculated location indicated that I was in the guest/sewing room rather than at my computer in the living room.

Tracking a bicycle ride

One of the apps tracks your movements. I assume that this uses GPS data and is not dependent on being connected to the network. I used this on a short ride that I believe includes areas that are out of coverage. I had the Droid in a handlebar bag and the Garmin mounted on the handlebar. On a 20 mile ride both units calculated the same moving time, distance and differed slightly on the altitude and total climb calculations.

I put the calculated tracks into Google Earth so that I could compare them side by side. Both tracks had errors. When compared to the rectified aerial photo I was all over the road and off the road for much of my ride. The Garmin seems to do a little better but that might be because it is set in a mode to attempt to follow the road. The errors were worse when I was in the trees. During one part of the ride the Droid seemed to have a consistent bias to the north of the road.

If I really cared about the accuracy I'd do some more tests with the Garmin set to ignore map information.

Navigating

I turned the navigation mode on for a 70 mile car trip home yesterday. The trip included a significant amount of time out of 3G coverage. I didn't observe the navigation continuously but checked a couple of times when we were out of coverage. The screen was white, showed no map data, and showed that the app was doing a rerouting.

So as I expected you can only navigate when you are in range of the towers.

When it is navigating the default is to have the screen backlight on continuously. The Droid actually feels warm after awhile.

Also yesterday I unplugged the Droid around 6:30 AM. We did a round trip through low and no signal areas, I made a couple of phone calls, I also connected to a WiFi network and viewed various web sites, for about 2 1/2 hours I had the navigation mode in use. The GPS and WiFi receivers were on for the whole day. When I got home around 6:30 PM the phone was begging for a recharge.

Conclusion

No surprises. With the current apps the Droid will not replace my stand-alone GPSR. If they offer a capability to store map data and calculate routes on the device then maybe it could replace it. Since my intended uses include camping based bicycling trips I have recharging issues that would limit how I would use the Droid. For a trip that doesn't include back country and has regular access to a USB power source it would probably be OK.

I am going to explore various off the grid recharging options such as solar cells and a new generator that runs off of body motion.

eTrex is not “all Garmins.” Those are the junky ones I personally refuse to use. My 5 year old GPS-60 series gets a position usually in 30 seconds or less, just for one example. Newer ones (with better AGPS and SIRFstarIII chips) are MUCH faster yet (single digit seconds).

Also, see the slightly older, less-bicycle-specific, but detailed review comparing S60 GPS to my Garmin unit: http://www.littlespringsdesign.com/blog/blog/2008/12/01/what-convergence/

Note a key issue (which seems to pan out, but remind me to take the dog for a walk with your Droid and the GPS60) is that they don’t agree. I won’t suffer straight-up inaccuracy so default to disregarding phones until proven correct.