c. GPS module

GPS module is GT PA6B type made on MTK chipset working at 38400 baud rate. Default configuration commands in OSD are made for this module.

In GUI is possible to set update position frequency 1Hz-10Hz and set WAAS for accurate position increase .

Also possible to edit configuration command frame to other types of GPS modules like ex. UBLOX etc .

GPS module have about 30cm long cable to be placed far away from rest of electronic to avoid jamming and glitches sources like Video TX and sometime camera etc.

So be sure to place GPS module as far from other equipment as possible .

About GPS accuracy of altitude . GPS was designed to show good position on the ground , altitude was something done "by the way" , but is available so is used also in OSD .

Altitude is better if more satellites are seen , at 8-10 satellites made altitude accuracy very satisfy . Sometime in cloudy days (or whatever reason) quantity of satellites seen during flight are changing so the accuracy of altitude will drift .

The best way before take-off , is to wait till 8-10 satellites are "in use" and then press "save home" button - this will set best accurate altitude as zero on airfield - then fly .

For GPS problems read here 09. Trobleshooting OSD

Now all GPS modules are build on PCB adapter what a bit increase weight but adding some advantages .

Older:

This increase mechanical integrity and increase resistance against mechanical damage .

Capacitor keep backup memory for about 4,5minute after power off , what is enough time to change battery or accidental OSD reset during pre- flight preparations .

This board also offers ability to connect external pins to use GPS's UART port and supply 5V (need to add protection diode) .

If anyone want, is also possible to connect external backup battery for unlimited (until backup voltage have at least 1,2V) backup time . Dedicated holes for gold pins are designed .

Older:

At last , when OSD will be too old to fly with or simply broken , is possible to use GPS module directly interfaced to PC , so miniGPS socket is designed to solder in . When USB cable is connected to GPS , PC will find out GPS module port , drivers are available to download from GlobalTop web side . I have tested such configuration with road navigation software on laptop in car - works perfectly .

Well, much better use in car an dedicated small Navi unit then a laptop - but that was just a sample of use :) .

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For proper work GPS module must be turned by antenna side to the sky :

Cables was connected directly to GPS module, to made weight as small as possible - obsolete

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