X12S Internal GPS Replacement

Since I got my hands on a second hand X12S to play with.
I am discovering all the possiblities of the built in sensors.

Main sensor what interests me is the internal GPS.
Why?, for experimenting with lua scripting 🙂

Last week I was working on a Plane finder script, It compares the coordinates of the transmitter gps, and model GPS, and calculates the distance. (LOS)
And Calculates the heading the plane is compared to north.

I have noticed the signal of the GPS is rather low, and has a very slow fix.

So I decided to take the TX apart and investigate the GPS hardware.
To my surprise, the whole UBLOX module is implementend on the LCD board.
And all UBLOX serial data is running via a seperate 4 wire cable.

I thought, “this can be a versy simple fix!”
I took my serial analyzer and looked what data is running there..
To my surprise the data running there is just plain NMEA @ 9600bd 1HZ.

As for all my OpenXsensor projects I use BN-220 Gpsses.
And by default.. you can gues it, they spit out NMEA data @ 9600bd/1HZ by default 😉

So I pulled out the cable from the mainboard. soldered an adapter cable.. and voila working!
( You can Use a smartport cable from a X4R / G-RX8  these are the same connectors like on the mainboard )

Now at the field I have a super fast fix within 10sec.. and mostly a fix between 12-20 satellites 😉


First of all remove the label at the back gently with an hairdryer.
This way you can remove the original patch antenna easily.
And stick back the label.

Secondly stick the BN-220 gps from the inside to the label.
Put a little bit of hotglue to fixate the GPS module.

The connect the BN-220 GPS to the mainboard with the adapter cable.

Wire Color Mainboard BN-220 GPS Wire Color
Green RX TX Green
White TX RX (Dont think this one is needed) White
Red 3.3V VCC VCC Red
Black GND GND Black

Enjoy the mod! 🙂

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