we have an small 4 in drone. We use the Matek F405 mini te flight controller.
this board have the * Baro: Goertek SPL06-001 (I2C)
The drone have a carbon frame with 3d printed electronics cover with some vent holes to cool the electronics and vtx with a very small 5v fan. We have covered the barometer with a lot of foam types and we dont have a correct barometer behaviour in AltHold. We have a lot of oscilations in altitude, dont keep the altitude. have a tendency to ascend. we have to correct the throtlle down to mantain the same altitude.
anybody have a best solution to isolate the baro in these “open” electronics flight controller?
Would need to see a log. Often with smaller drones the issue is the filtering + loop rate + Z PIDs. You are not going to be able to increase the loop rate but you might be able to get higher filtering settings. Make sure you fully follow the tuning guide. Initial Tuning Flight — Copter documentation
the use of this drone its the following. no gps installed (indoor use only)
normal use in althold with baro as alt source.
loiter mode for hover and use the optical flow to fix position and the lidar for the alt, switch on by rc.
we use the lidar only in loiter mode to mantain position.
in normal mode we dont use the lidar, because then, we dont can make multilevel flights, enter in windows, upwards to upper levels. with the lidar on, the drone mantain altitude over this ground, and if you enter by a window or any hole in the upper level, the drone ascents a lot to mantain these altitude. by these issue, we use to normal flight the alt hold mode with baro
it could be a lot if things causing that, other than pressure changes.
A log would be needed to figure out what’s causing this.
To isolate the barometer some foam should do the trick, also make sure that the fan won’t blow air into an enclosed of partially enclosed space. That might cause an over pressure inside of the housing if the exit holes are too small. Also make sure that the fan won’t blow directly on the flight controller or that air could be deflected of any surface and hit the barometer.
But post a log so that we know for sure if it’s actually the barro.
we remove the fan to check the issue, and the behaviour its the same. the fan dont cause the baro oscilations.
we put a lot of different types of foam. with 5mm foam between the fc and the esc, a little tight, we found the best results. only oscilates a litlle in the beginning of the flight, one minute ago, the baro keeps altitude much better
You still need to post a log if you want to find the root cause. Like Andy said, there could be other issues causing this. Even if the barometer needed better insulation, there could be other issues as well