GlobalSat GPS Receiver

GlobalSat GPS receiver

I worked with a GlobalSat GPS receiver in the Sirf Binary Protocol. My project required me to use Labview to collect data from the unit. I went into so much trouble trying to convert the binary messages into meaningful text and numbers. My main issue was to convert Sirf HEX into singles and doubles. My unit reported that the firmware was GSW 3.25 but the format that was specified in the protocol manual did not work on the binary messages I got; I used to get numbers in the orders of 300. You may read my forum post here.

After much trial and error I realized that the doubles were arranged in the same format as earlier versions of the firmware (which is contrary to what the manual says). Expected byte arrangement of doubles : B0 B1….. B7 Correct byte arrangement of doubles : B3 B2 B1 B0 B7 B6 B5 B4 To read these in Labview, I had to reverse the “Correct” order. For singles, I reversed the order they have in the manual, (little/Big endian issue).

Check the Automated Systems and Robotics Laboratory Site for updates.

Lab project – Research work
Time line Summer 2011
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