GPS + KTM = TMF (Too Much Fun!)

by Peter_vdL Motorola 06-20-2011 08:10 AM - edited 06-21-2011 08:47 AM

David Thomson is a keen Android user and MOTODEV member, who explores off-road areas by trail bike every chance he gets.   David rides an Austrian-made KTM 640 Adventure - a bike with enough power to take you off the edge of one map sheet, clear across to another.

When you explore the wilderness, it's handy to have a GPS unit that shows and logs your location on a map.  The cheapest GPS is still more expensive than the GPS that you already have in your smartphone.   With this in mind, David's project was born - build a mount to hold and power his Motorola DROID phone on his motorcycle.

Before starting the project, David wondered about the vibration tolerance of the phone.  So, in the true spirit of science, he did some vibration measurements, first on a car (for which phone mounts are available, so we know phones can tolerate that level of vibration).   And then on a motorbike, to see how far it was from the car spec.   He used an Android App called "vibration meter" to compare frequency and amplitude  between the motorcycle mount and the Motorola car mount (suction cup to windshield).  Vibration meter  is a free app in the Android market.

The car mount gave a vibration reading in the 5's on the Mercalli scale (~3.5 Richter), while the motorcycle was in the 6's (~4.5 Richter).  That is a tenfold increase in wave amplitude between bike and car!  So a vibration-damping motorbike mount looks like a serious problem.  David solved most of the problem by using an off-the-shelf enclosure for the phone.  He choose the Aqua Box from RAM Mounts.  This is the transparent-lidded box in the picture below.   It comes complete with base mounting hardware, that was drilled and screwed onto the bike's instrument console.


                                           The completed phone mount on David's motorcycle


All that was needed now was a USB connection, to charge the phone from the bike. David used an off the shelf micro USB cable to bring USB into the aqua box and then the phone.  The USB cable was made by 3BRPowersports, who fabricated a custom cable with a 2-pin Molex connector on the end, to plug it into an unused connector under the bike's dashboard.  The voltage comes out of the stator at a nominal 12V, that actually varies depending on the engine's RPM.  Much less than this reaches the USB power cable, as the bike's draw is significant.  The cable maker has a voltage regulator in the cable that only allows USB-spec power through; this was carefully tested before connecting the phone! 


David used the old "trick" of a fridge magnet to trigger the phone’s “Car Dock” mode to switch to using big buttons on the Droid screen.  The phone tracks and displays his location while he moves.  He uses the free OruxMaps App to acquire the maps and store them, so a (costly) data connection is not needed at "run" time.   This is an excellent and ingenious "hack" in the best sense of the word.   There's a longer account by David here.


Do you have a story similar to the one described above? What out-of-the-box ideas have you had for personalizing your phone for your own needs? 


Let us know by leaving a comment below or post on our Facebook wall at:


By Nicole McMorran (Social Media Manager) and Peter van der Linden (Android Technology Evangelist)

by DT(anon) on 06-22-2011 09:39 AM

Thanks Peter!  


I just wanted to offer a link to the Motorola Owner's Forum where I got a good reply from someone who seemed to know a bit about vibration tolerance of electronics:


ek_skotous noted that Motorola's guidance was to not drop your phone, and while I don't want to test my phone this way - yikes - I did use Android Boy's "Vibration Meter", to get a value to compare with the vehicle-mounted values, just by firmly hitting the phone against the palm of my hand causes the readings to reach near 9.0, which is a thousand-fold increase over the 6.0s on the motorcycle!  (log scale) 


So I am fairly confident the vibrations are not excessive, but my ongoing questions concern the other variables: heat and moisture.  I am fairly certain the AquaBox (or my Otterbox 1900 which I will be using on a boat, but that is another story... ) are good at keeping moisture out, but heat remains a concern for me.  I even have this concern with the Motorola car windshield mount, which I don't leave it in for long, but it gets pretty hot just on short trips around the area. 


Other random notes are (1) the AquaBox has a soft screen that allows me to use the capacative touchscreen controls of the Droid; the only issue being if the phone's screen turns off I have to open the box to turn it back on with the power button, and I wish there was a way to do that with the screen.  And (2) I am still working on the right mapping app for me; Orux may be it, but I have had difficult downloading and setting up my offline maps with the methods used for it.  There are many others that I can list if anyone is interested. 

by evelyngermaine4 on 03-27-2012 10:38 AM

I think having the phone actually mounted onto the bike is a great idea. As far as apps go, I've enjoyed using the cheapest gas finder app. On a more personal note, I wish more people would learn to ride a motorcycle! So many roads open up to you, literally. Especially if you like off roading, and with all the programs the new phones have, getting lost or stuck isn't that much of a risk anymore!

by Car GPS(anon) on 07-16-2012 01:15 AM
by Peter_vdL Motorola on 07-16-2012 08:23 AM

Thanks for the great feedback - I hope to see more of you in the forums.   There are some new posts coming this week - I'm working on one now!



Android Technology Evangelist.

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