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Archived Boards and Threads => Archived Boards => FAQ GlobalTop GPS Receivers and Modules => Topic started by: Horsa on June 07, 2010, 01:05:49 PM

Title: How do I configure fix-rates up to 10 Hz?
Post by: Horsa on June 07, 2010, 01:05:49 PM
Q: How do I configure fix-rates up to 10 Hz?

GlobalTop modules and receivers based on MediaTek MT2239 chip support fix-rates up to 10 Hz.
The tool MediaTek Mini GPS version 1.4 allows to change the fix rate up to 5 Hz.
To configure fix-rates up to 10 Hz, you should follow the directions described in the document
Using WinXP Hyperterminal to change MTK GPS setting.pdf
available on our documentation server
    http://www.trenz-electronic.de/download/d0/GlobalTop_Technology.html (http://www.trenz-electronic.de/download/d0/GlobalTop_Technology.html)

In the same folder, we put also some hardware-verified reference commands.
Please make sure that the new fix-rate dos not saturate the available throughput capacity of the current communication port (Setup panel of the MediaTek Mini GPS tool).

If NMEA (for example GGA) interval is set to 1 and the fix-rate is set to 10Hz, it means that the GPS module or receiver will output the GGA sentence 10 times per second. If the sentence interval is set to 2, and the fix-rate remains the same, the GPS module or receiver will now output the GGA sentence 5 times per second. If the sentence interval is set to 5, then the GPS module or receiver will output the GGA sentence 2 times per second. The value output in each sentence is not a mean value of other internally computed values, but actual and unique computed values. The fix rate just sets the intensity of calculation you want the GPS engine to perform. No values are discarded. Higher fix-rates also mean higher power consumption as the module needs to work harder to compute more volues.

Settings configured by commands are volatile. If you need your own default settings different from GlobalTop default settings, we recommend you to contact us before buying your module(s), so that we can have GlobalTop program the internal Flash memory with your own settings for free.