HelloI should know this but wanted someone to chime in pleaseI am using 3,1RC7 on all of my hexacoptersIf I travel to a flying field, let's say 120km away do I need to recalibrate my compass? I am using all APM 2.6Thanks! JEFF
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We've discussed this in the dev group as well and the answer is "No", it's not necessary to re-do the "live calibration". What you're doing with the live calibration is calculating the 'static' offsets which accounts for the bits of metal in the board and on your frame. So this calibration only needs to be redone if you say add a hunk of metal to your frame or move your flight controller around on the frame (or change the compass). We've confirmed this because the guys in the 3dr factory in Tijuana make RTF copters and they've shipped them up to SanDiego and Craig & co have redone the offsets and get the same values.
What changes when the copter's taken to a new location is the declination and the mag-field length. The code actually looks up the declination based upon it's first good GPS location so you shouldn't have to mess with that either...and there's nothing we can do about the mag-field length and the direction of the vector should still be correct..it's just shorter or longer.
My guess if you travel north-south probably not a problem, east-west maybe. 120 miles maybe not. I imagine you have to get probably over 300 or 500 miles to have an issue.
I fly a Quad and a Y-6 at several different fields and haven't re-calibrated my compass. The only thing I notice is when I switch fields I have to check via Mission Planner that my copters are showing level prior to arming and also you can check for compass heading. Not sure if it's change in altitude or air pressure that throws it off level. But letting it sit prior to first flight seems to straighten it out. I am using 3.0.1 firmware. Hope this helps.
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We've discussed this in the dev group as well and the answer is "No", it's not necessary to re-do the "live calibration". What you're doing with the live calibration is calculating the 'static' offsets which accounts for the bits of metal in the board and on your frame. So this calibration only needs to be redone if you say add a hunk of metal to your frame or move your flight controller around on the frame (or change the compass). We've confirmed this because the guys in the 3dr factory in Tijuana make RTF copters and they've shipped them up to SanDiego and Craig & co have redone the offsets and get the same values.
What changes when the copter's taken to a new location is the declination and the mag-field length. The code actually looks up the declination based upon it's first good GPS location so you shouldn't have to mess with that either...and there's nothing we can do about the mag-field length and the direction of the vector should still be correct..it's just shorter or longer.
hope that helps!
I fly a Quad and a Y-6 at several different fields and haven't re-calibrated my compass. The only thing I notice is when I switch fields I have to check via Mission Planner that my copters are showing level prior to arming and also you can check for compass heading. Not sure if it's change in altitude or air pressure that throws it off level. But letting it sit prior to first flight seems to straighten it out. I am using 3.0.1 firmware. Hope this helps.
I am curious about this also.