RTK with ARDUPILOT over MAVLINK
You can use the telemetry of UAV (any of compatible models) for send the RTCM messages from a laptop to the RTKITE
https://www.youtube.com/watch?v=4wkQepaMJVY
Follow these steps in RTKITE
0) FACTORY RESET to erase all previous setup
1) Connect with the App and press "Get" to read the current setup (must be Drone UHF)
2) Change Output Mode to "5Hz Ardupilot Nova"
3) Change RTCM Input baud to 115200 for Pin 6 of RTKITE (Wired to the Pin 2 of Pixhawk)
4) Press "Set" to take effect and the RTKITE will made a reboot.
For the Pixhawk o Pixhawk 2.1 you have to recompile the code and remove the blob initialization in NOVA driver (ask us help if you need it)
Changes in AP_GPS_NOVA.cpp
Changes in AP_GPS_NOVA.h
The files modified
Be sure to setup Mission Planer with protocol NOVA (15). See this note
http://support.northsurveying.com/knowledgebase.php?article=12
Finally setup, Mission Planner-> Initial Setup-> Optional Hardware-> RTK\GPS inject for transport the RTCM to RTKITE
If you need, here are the PRECOMPILED Pixhawk firmwares updates for Copter 3.6.0-rc12 05-Oct-2018
Pixhawk (older Pixhawks that suffer from the 1MB flash limit issue)
Pixhawk 2.1 (Pixhawk2/Cube and newer Pixhawks with no 1MB flash limit issue)
FMUv3 (Pixhawk2/Cube using ChibiOS)