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F5529LP + GPS MT3339 + RockBlock7 9602 Iridium Sat-Comm DIY "spot me"

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My wife wants to know that when I do my John Muir Trail trek starting on 7/26/2016 I've not fallen down and can't get up, or been eaten by a bear...

So, I've been building my DIY "SpotMe" Iridium Network-based GPS-Satellite Comm device. 

I've gotten to the basic level of communication; It reports my position on a regular basis (the following is from a morning conditioning hike). 

To my surprise, when I set the deconstructed system up on my kitchen table, it managed to both get a GPS fix AND successfully transmit the data to an Iridium satellite.  Given that there is really no "sky" visible from my kitchen, a better than expected performance! 

Why build it when I could buy similar? Well, why not???  :) Similar to Dave Jones' "take it apart" I'm a firm believer in DIY to figure out how something works, and can I make one... :)


Future travel plans: I do "Iron Butt" rides on my 2005 ST1300 - now with 175,000+ miles (there's no typo there, I've really driven that far on my bike...), and I'm planning to do 300 mile sections of the Pacific Crest Trail for the next 10 years. So, again, keeping the wife happy and "in the know."  So, this will be something I plan to use on a regular basis over the next several years.


Once finished with the project I will publish all code, hex and design files for those who have an interest.


Finally, thanks to all who have helped me.  Especially Robert Woodruff, yyrkoon, and Spirilis.




http://www.nursebobsblog.org - currently stale content, updates planned for after the hike and teaching again...


On 7/14/2016 at 09:01:47 PDT Bob was here:  https://www.google.com/#q=%2B38.564295,-122.432641 -Aprx Elev.: 1676 ft
On 7/14/2016 at 09:14:44 PDT Bob was here:  https://www.google.com/#q=%2B38.572575,-122.428550 -Aprx Elev.: 1645 ft
On 7/14/2016 at 09:25:53 PDT Bob was here:  https://www.google.com/#q=%2B38.575296,-122.433725 -Aprx Elev.: 1644 ft
On 7/14/2016 at 09:36:38 PDT Bob was here:  https://www.google.com/#q=%2B38.580748,-122.431888 -Aprx Elev.: 1784 ft
On 7/14/2016 at 09:50:50 PDT Bob was here:  https://www.google.com/#q=%2B38.582575,-122.431873 -Aprx Elev.: 1743 ft
On 7/14/2016 at 10:05:25 PDT Bob was here:  https://www.google.com/#q=%2B38.574358,-122.427476 -Aprx Elev.: 1564 ft
On 7/14/2016 at 10:16:14 PDT Bob was here:  https://www.google.com/#q=%2B38.569375,-122.423606 -Aprx Elev.: 1740 ft

No visible sky, from inside my kitchen:
On 7/14/2016 at 11:34:57 PDT Bob was here:  https://www.google.com/#q=%2B38.539415,-122.471001 -Aprx Elev.: 593 ft



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The ST has been, by far, the best bike I've owned. The first five bikes were Suzukis, this is my first Honda, and given its reliability, it may be my last.

RE: the DIY spotme, I hope to have some energy consumption numbers by the end of next week. The RockBlock draws a ton of current (by '430 standards), but only when communicating with a satellite. Based on what I've seen with the system so far, the GPS is "on" for under a minute, and the 9602 for about 5-7 minutes per hour, and it only draws significant current (450mA for a about 10 milliseconds) when actually talking to a satellite.  It should be interesting to see what the actual power requirements are, and if I'll need to recharge the battery while on the hike.

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I am interested in the pricing model for the sat comm ... could you give some details, please [emoji4]

I bought the device from Sparkfun for $250.00, There are various suppliers.  The one I have (9602) has been superceeded by the 9603, which supports longer messages.  Contrary to what's published on Sparfun's site, the 9602 does NOT support messages longer than 120 charaters.

The subscription to access the satellites is about $12/month, and then there's a per-message charge.  The pricing model can be found at:



The couple of support questions I had were quickly and efficiently addressed.  My only complaint would be what they consider to be a data/spec sheet I would call advertising.  Very weak on the technical specs...

FWIW I was able to use Mikal Hart's IridiumSBD library  as a drop-in.  I also had success with his TinyGPD++, though I ultimately found that the GPS code did far more than I needed, and at times had issues with the Energia code's use of the '430's low power modes.

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