I have problem with one of my APM2.5. One of my APM when on the ground shows between minus 0.60 meter to minus 1.00 fluctuating. If Ilift the quad to 1.6 meter the altitude shown on the mission planner become positive and indicate 1.00 meter. When I put the quad back on the ground the reading become minus 1.00 descending very slowly to minus 0.60 or minus 1.00. I think that the barometer is not right. Could one of developers advise me? Note that even with GPS lock and 3D fix the altitude is not right. The other APM 2.5 give me the right reading.
Thank you. Pierre
Replies
The height displayed in the mission planner is not necessarily baro height. It is the calculated height that is used by the copter, which could be sonar, baro, gps or a combination of those, depending on your config.
If you wanna test baro, take the gps and sonar off, reboot and then see what it does. GPS height can easily be off by 1 to 10m, depending on how many sattelites you have and where those sattelites are in the sky. do if the AHRS takes gps height into calculation your height will vary and/or be wrong.
Alternatively, you can go into CLI (terminal in the mission planner) and type test and then ? to see the possible tests. I think baro is amongst them.
Note that the baro is very sensitive to light, temperature and pressure difference. Breathing on it is sufficient to disturb it if it's not covered with a piece of foam. Also preferably let it sit in the room for 15min before testing. Bringing it from a cold environment into a warm one can disturb it also.
The developers develop software, 3DR designs and produces the hardware.
I am interested in this topic. My APM 2.0 does almost the exact same thing. I have never looked into it because I didn't think to compare it to anther APM. My friend has one, maybe I need to get them side by side and check.