I have some success using the ZED-F9P (Both ArduSimple and CSG shop module) for RTK navigation. However, I found that with ZED-F9P the ArduCopter no longer have the correct timestamp. Timestamp shows 1980 January for all the mission with the ZED-F9P module.
I found that, the time of the week is missing and cause this issue. Upon further investigation and some digging in the ArduCopter code, I found that in ardupilot/libraries/AP_GPS/AP_GPS_UBLOX.cpp the time_week get from the UBX-NAV-SOL message. Then, the time_week and time_week_ms was used to covert into the system time in AP_GPS. However, based on this document, the ZED-F9P is using UBX version 27.10 protocol (uBlox 9). In this new version of the protocol, the UBX-NAV-SOL is no longer generated with the module. I could not really find another source of week number in NAV group. Seems like uBlox finally did away with NAV-SOL message. Will uBlox 9 be supported for future version of the ArduPilot?
Currently, I am thinking about the work around. Since UBX-NAV-PVT provide UTC time in yyyy/mm/dd/h/m/s and time accuracy estimate in nano second, we can use the UTC time to calculate the week number and pass it to the time_week.
No at all. The navigation part works great. The navigation part of the ZED-F9P works great! ArduPilot is using the UBX-NAV-PVT for the navigation anyway. If you have the control system tune properly, the landing precision/position holding is pretty good. I have some operation depends on the high accuracy timestamp that provided by the GPS. Thus the system time is important to us. Just in term of the RTK navigation, ZED-F9P is pretty great.
I did not try the Drotek module myself. However, I would imagine it should not make any different. The ZED-F9P is very compact module. All the board does is bring out the interface for different form factor. ArduSimple is kinda big is due to they have build-in xBee interface. You can “saw” the board in half it would still work fine. It seems now that beside the not have UBX-NAV-SOL, uBlox 9 (the one ZED use) is pretty similar to the older version uBlox protocol (ArduPilot based on).
How’s your F9P configured for 5Hz RTK ? I couldn’t manage 5Hz using more then GPS + Glonass, and for 10 Hz I had to drop to GPS-only.
I had a pair of Ardusimples to test, and the more I looked at specs versus results, the more I started to question my driver. I tried a couple of driver changes but it only made matters worse
I have no problem using 5HZ RTK with GPS+Glonass+Galileo+Beidou when it is on the drone. I used the ArduCopter auto configure that has update rate 200 ms, Airborn4G navfilter. With in the GPS, I choose to use all constellation. What problem do you run into? When test on computer, I used the default windows driver. I also used it as Ntrip client/server using raspberry pi and it works fine with both USB and UART.