how do you have your RPi/Navio combo mounted on your multicopter frames?
I cut a piece of plywood and screwed it under the RPi, then I added four blocks of doublesided foam tape (10 layers) to each corner.
The blocks stick to the upper plate of my frame.
I went outside to do an autotune, but the Althold behaved erratically and so I just flew around a bit with the standard values.
I checked the dataflash logs and had a whole lot of vibration, so I took the antivibration mount from the APM2.5 I had on this copter before and mounted the RPi/Navio on it
I did a short flight in my livingroom and it was almost the last, because I had almost no throttle control, the copter just went up and down and nearly crashed into the ceiling (stabilize mode)
While I was fighting to get it on the ground in one piece, I could see the RPi/Navio shake like mad on the antivibration mount.
I guess the RPi/Navio was just to heavy for it.
The copter has balanced T-Motor MN3110 780kV swinging balanced 11x5 Aeronaut props.
I also balanced motors and props dynamically together.
Now I am in need of some proven mounting methods.
Here are the screenshots showing the vibration graph from both tries:
Those are the vibration graphs for x y (red/green) and z (blue) direction. Z is up/down, x is forward/backward (I think) and y is left/right.
The values are taken from the accelerometer and get recorded by the APM firmware during flights. The logs are to be found in /var/APM/logs/.
Have a look at copter.ardupilot.com and search for vibration.
If you want something answered, answer it yourself
I had a look at the arducopter wiki and adopted an antivibration mount listed there for the RPi/Navio combo.
Here are the results of a short hover flight indoors:
I also tried to make a plate with dampening but rubbers turned out to be too soft and Navio+ was shaking like crazy. Finally I just hard mounted it and it works fine.
Saw your video on YouTube, looks like you already got Summer there
Oh, I totally forgot about the video. Going to add some tags and a description. It is like an on/off summer at the moment. I was lucky to catch a sunny moment, with calm winds.
Did you have a look at the vibration levels, with the Navio hard mounted?
Just to know if I wasted my time…
I just drilled four holes through the plywood, matching the pattern of the holes in the RPi. I used prop adapters as spacers between plywood and RPi (the black pieces you can see in the pictures) and used longer M2.5 screws to reach the standoffs provided with the NAVIO+.
DIY Frame
T-Motor MN3110 780kV
11x5 aeronaut cam light props
4in1 20A qbrain ESC
4000mAh 4s Zippy compact Lipo
AUW with FPV gear and Gopro 3 in its case
is
1605g
Flying (not hovering) time is about 12min with 20-25% left directly after flight.
Ok, this is driving me nuts.
I am just back from a testflight.
Autotuning with AC3.3-dev from the apm.deb was not successfull, because the copter was keeping its attitude and not returning to level flight after releasing the sticks in stabilize mode.
GPS was great with 16 sats, I never saw that before.
Here is the a screenshot:
I then compiled AC3.3-rc3 from the diydrones repository and went out to fly.
Autotune did go through all three axes and after landing and starting again, the same old problem was there again.
Flying fast forward/backward/sideways, releasing the sticks and the copter just keeps on going, perhaps returning a few degrees to level, but from 45° max to 40° or so, with sticks in the middle. I had to manually counter the attitude, like flying in rate/acro mode.
I wanted to check the values with my laptop, tried to engage PosHold mode, but nothing happened.
I landed, went to my laptop and noticed the copter had no GPS fix, not a single sat.
After restarting the APMCopter.elf I did another flight, this is the GPS log:
not really what I wanted to see, but at least it has a few sats.
The next flight, I just changed the lipo after a clean shutdown, looked like this:
Flatline again
I only flew for a few seconds, but I left the copter powered on the ground for about 5mins and still no sats at all.
The vibration log is strange, too. This is the same flight as the first GPS picture:
This is the second flight:
I changed nothing except for the lipo between the two flights, yet the vibration log seems to show two different copters.
