You can set GPS coordinates in your Phantom FC40 and have it fly there autonomously.
This is one way to do it for less that $10 worth of parts.
Let me start by saying do not do this mod unless you are VERY confident of your electronics skills.
I DO NOT KNOW THE LEGALITY OF DOING THIS SO DECIDE FOR YOURSELF.
Also be prepared to loose your Phantom if you program the wrong remote home point coordinates.
Suggest to only fly this mod in non populated area and the first time for a short distance.
If in the short distance test something doesn't seem right switch from fail safe to ATTI mode.
I have tested this mod several times and it does work good, don't blame me if something goes wrong.
I am not recommending this mod and am presenting it here in the case that someone is interested.
The following is how to apply remote home point coordinates.
Farther down I will describe all the software and hardware necessary.
Get GPS coordinates for desired remote home point from Google Maps, Earth or a GPS in
decimal degree DD.DDDDDD format. Be aware Google Maps may be offset from actual coordinates.
Set GPS Emulator parameters and start output.
Power up Phantom by connecting battery.
Wait for NAZA to GPS handshake, "first set of fast blinking light" takes about 5 seconds.
Plug in the 3.5mm serial jack "this interrupts data from GPS and injects data from Emulator.
Caution the next step will require starting motors, remove props or use extreme caution!
Using transmitter start motors "this sets the home point for coordinates set in GPS Emulator"
Using transmitter stop motors and disconnect 3.5mm serial plug from jack.
Don't disconnect battery or home point will be erased. You can turn off transmitter if desired.
Compass calibration can be performed before flight if Phantom has been subject to magnet or metal.
Before flight make sure the LED is blinking green 6+ satellites.
Launch Phantom with enough altitude to avoid any obstacles on rout to remote home point.
Switch transmitter off or set S1 to fail safe.
Phantom will go to remote home point coordinates and land.
Hardware mod:
It will be necessary to convert the active low GPS data to active high that your computers
serial port can read and to convert the computers serial data to active low for the NAZA to read.
This is the purpose of the two transistor circuit.
Using the schematic for reference cut the G-T trace on the GPS modules daughter board and apply transistors,
resistors, wiring, and jack. You will also need to make a cable to go from computers serial port to Phantom.
When the 3.5mm stereo plug is removed the switch in the jack will loop the data back in for normal operation.
When plugged in the GPS data will go in the ring to pin 2 on db9F and data will go from pin 3 on db9F to tip.
Software:
You will need two pieces of software well just one really, GPSEmulator.exe for outputting U-BLOX sentences.
If you want to read the GPS data for troubleshooting then U-CENTER is nice to have, both are free.
U-center
http://www.ublox.com/images/Support/Sup ... _v8.13.zip
GPS Emulator
http://www.happykillmore.com/Software/R ... igTool.zip
You don't have to install GPSEmulator.exe just run it from the unzipped folder.
Ignore the other files in the folder and configure with the following settings.
GPS Emulator settings
Check the following uBlox sentences only.
NAV-STATUS 'Navigation Status'
NAV-POSLLH 'Geodetic Position'
NAV-DOP 'Dilution of Precision'
NAV-VELNED 'Velocity in WGS 84'
NAV-TIMEUTC 'Universal Time Coordinated'
NAV-SOL 'Navigation Solution'
NAV-SVINFO 'Satellite Status and Information'
Baud 57.600
Hertz 4
Precision Format DD.DDDDDD
Speed slider down-0
Set Pitch slider to just above ground elevation for Lat. and Lon. Can get from Google Earth.
Start Laittitude DD.DDDDDD Get from Google Earth. Make sure to set N for North and S for South.
Start Longitude DD.DDDDDD Get from Google Earth. Make sure to set E for East and W for West.