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Allspice Node GPS | by nebarnix
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Allspice Node GPS

Ok this one will take some explaining :)


First of all, the red line shows velocity vs altitude, so the higher the line, the faster I was driving.


Ginger , that wireless system for high altitude balloon systems, is a network of low power wireless sensor nodes that interface with a high power ground link. Pressure, temperature, telemetry and link information have all been flown before successfuly. GPS was a major obstacle due to the importance of tracking and the flexibility this would allow for onboard instruments to know their own location.


GPS units that can fly to greater than 60,000 ft are difficult to find, but after buying a U-Blox module from sparkfun, I looked at the config tool and besides reprogramming the hell out of the firmware I realized that there is an aviation mode -- good to 160,000 ft!!


I coupled the node to an Allspice PC-link Node and starting writing code like there was no tomorrow. The result is here.


The node is a small wireless device with a relatively low range (50m or so best case). It was placed on my dashboard powered by a 3.8V 300mAH lithium polymer battery.


The software running on Erica's laptop was custom written and converts the GPS packets (as well as status packets indicating link margins and temperatures) into two KML files. One is a network link which allows the other to be refreshed once a second to update the new location. TSV data files and traffic logs are also generated.


We drove all the way across Mesa, AZ to pick up another Guinea Pig for Irwin (who is a lonely pig, but no longer!). As we drove, we used the application to track our progress. Overkill for automotive applications but the test was a success!


Not only is the Ublox module incredible (the trail starts on my desk inside of my house and never loses its fix), but the software ran perfectly and the data was logged in KML, TSV, and HTML form. if the laptop would have crashed, no data would have been lost that had already been received.


The next step is to send this back to VAST in moscow and have them test it with the high power transceivers. The new 915MHz 10 Watt units should work for hundreds of miles (LOS)

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Taken on February 22, 2009