Difference between revisions of "GPS"
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* [http://www.egnos-pro.esa.int/IMAGEtech/imagetech_realtime_html.html EGNOS Real Time Performance] | * [http://www.egnos-pro.esa.int/IMAGEtech/imagetech_realtime_html.html EGNOS Real Time Performance] | ||
* [http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=81990 Discussing MTK receivers and Tips and Tweaks] | * [http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=81990 Discussing MTK receivers and Tips and Tweaks] | ||
* [http://www.pocketgpsworld.com/modules.php?name=FAQ&myfaq=yes&id_cat=1&categories=Basic+GPS+Theory#9 GPS terminology] | |||
Revision as of 14:22, 1 April 2008
As of today (March 2008) the two best GPS chipsets available are the SiRF Star III and MTK MT3318. They offer fast initial fix and can utilize weak GPS signals by massive parallel correlation computing power [1].
SiRF Star III
Disable DGPS
To disable differential GPS correction, either use the SiRF Demo program [2] or these commands to disable WAAS/EGNOS/MTSAT [3]:
$PSRF100,0,38400,8,1,0*3C ; Switch to SiRF mode $PSRF151,00*0E ; WAAS/EGNOS/MTSAT Off $PSRF151,01*0F ; WAAS/EGNOS/MTSAT On
SiRF commands
MTK MT3318
Enable 5 Hz
The default update frequency is 1 Hz, or once per second, the MTK chipsets support 5 Hz.
$PMTK300,200,0,0,0,0*2F ; Set 200 millisecond update frequency $PMTK251,115200*1F ; Baud rate 115200 $PMTK300,200,0,0,0,0*2F ; ; Again set update frequency
Hacks
MTK commands
Other chipset brands
- SkyTraq
- Nemerix
- uBlox
- uNav
- Sony
- Fujitsu
