I’ve been able to successfully install Arducopter ArduCopter V3.6.0-rc10 onto the Pixhawk 4 via Mission Planner, but I’ve ran into an issue: Changes made to any parameters are not being saved, hence all parameters are defaulting upon power cycle. I can make parameter changes, write those changes, verify changes by refreshing the parameter list, but as soon as I power cycle those changes are lost.
Any advice would be much appreciated 
Are you by chance changing SYSID_SW_MREV to zero when you’re loading/changing parameters? Because that initiates a parameter reset on reboot.
No, haven’t made any changes to SYSID_SW_MREV. After further mucking about my issues of parameters not saving morphed into parameters occasionally saving with occasional parameter corruption issues. I’m really at a loss on this as my previous Arducopter experience was with a Navio2 with zero issues at all.
Think that I’m going to switch the Pixhawk4 back to PX4 v1.8 until Arducopter has a proven stable release for the Pixhawk4.
My understanding is that the Pixhawk4 should work.
Any chance you could provide a dataflash log file? Maybe the wrong board is being recognised or something. Anyway, without a log it’s hard to say much…
hi @Joe_Rogers, I’ve just tested on a Pixhawk4 here and parameter saving is working fine. I did however receive one prototype Pixhawk4-mini board from Holybro that had a bad FRAM chip (the FRAM chip is the one that is used to save parameters). So it is possible you have a bad board.
I should also mention that if the FRAM doesn’t work then ArduPilot will fall back to storing parameters on the microSD card. Do you have a microSD card inserted? Does saving logs work?
The parameter file on microSD will be called APM/ArduCopter.stg
Cheers, Tridge
The only other thing I can think of is if you were trying to load a full parameter list that was saved using a different board. In that case you could be loading a critical parameter related to board type that would cause the board to not work properly.
Can you tell us exactly what parameters you are setting?
I have similar issue with Ardupilot and Holybro Pixhawk 4. BUT! Parameters are saved as zeros.
So, after firmware installation it is not possible to set frame type. If I try to change any parameter, it is immediately set as 0. PARAM_VALUE in MAVLink inspector returns with 0 value.
After rebooting, edited parameters remain as 0.
I tried to choose different boards with fmu_v5 for firmware installation, the result is the same. ArduCopter, ArduRover, ArduPlane - the same.
On SD card I can see newly created APM/ArduCopter.bak.
Saving parameters with PX4 firmware works fine.
Any ideas would be helpful. Thanks.
Well… I succeeded to save parameters with MAVProxy command line. So, this issue seems to be on QGroundControl side?
