Quick advice before I pay DJI !!!

I can't honestly say I know how the GPS works. But everything I've read is that a proper compass calibration will put the MOD value ~1500. If it's far away from that, then upon lift off, it will take off. A compass calibration is a reference point for the phantom. If your reference point is skewed on one of the coordinates, it will react. The gimbal also relies on that and if you look at some flyaway videos, the gimbal or horizon is lol over the place.

Case in point. I calibrated my phantom over an open field. I flew it three times. On the last flight. I set my phantom down about 15 feet from my truck and on concrete with rebar. I lifted off and it came right at me. I immediately shifted to atti mode, got orientation and height and then landed. My mod value was 1950. From then on, I always check that value before flight to know I have a proper compass calibration. It quick. And over 200 flights, I've only has one fly away that I was able to recover from. The one that taught me to look at the mod value there after. If you take anything away....do that
Hey man I'm a newbie, but keen to learn. Only had my P3 for a few days, but eventually will be flying off a boat (my home). Hate the thought of no control over the ocean. Where do I find that MOD value.
Norm
 
Go to the menu of the drone in the go app. In the sensitivity tab, it will show you the compass values. Just look t the MOD value. Go to that menu before you ever lift off and verify. You don't have to do a compass calibration all the time. Just if you change location or at the first off the day.
 
Go to the menu of the drone in the go app. In the sensitivity tab, it will show you the compass values. Just look t the MOD value. Go to that menu before you ever lift off and verify. You don't have to do a compass calibration all the time. Just if you change location or at the first off the day.
Thanks Buck.
I'll definitely get into that habit. Will give it a try next time out. Too windy today.
Thanks again.
 
On the death flight, home point was set, it took off and hovered to about 8 feet, I pushed it forward a few feet and hovered it again. Then when I proceeded to go forward slowly, is when it took off from me. It didn't just lose it from the get go, there was full control for the first 10 seconds. To me, what happened was inexcusable.
 
On the death flight, home point was set, it took off and hovered to about 8 feet, I pushed it forward a few feet and hovered it again. Then when I proceeded to go forward slowly, is when it took off from me. It didn't just lose it from the get go, there was full control for the first 10 seconds. To me, what happened was inexcusable.

What was your Mod value? If you don't know, then you don't know if the calibration was good. Yes, I know you may of had a green light on the banner. I think the log file will contain those values for that flight.n I've yet to find it, but I haven't looked very hard. ....and it's possible that something just broke and a part failed. And if it did, DJI should pick up all the costs. I'm getting that they didn't say as much
 
So if I'm learning anything from this, it's that the GPS lock onto multiple satellites from multiple GPS systems absolutely means nothing.

That's kinda true I would say.

Well, it means that at that moment, you are receiving a signal from those satellites. But that signal can come and go quite a bit. There is likely some "averaging over time" algorithm calculating the average number of GPS signals received and the average strength over a specific time.

Does someone know exactly how it works with the Phantom?

GPS is not a guaranteed service. Solar interference can disrupt GPS signals at ANY time. Learning to fly in ATTI mode and being prepared to switch quickly to ATTI mode when the Phantom starts acting erratically is probably a very good idea.
 
What was your Mod value? If you don't know, then you don't know if the calibration was good. Yes, I know you may of had a green light on the banner. I think the log file will contain those values for that flight.n I've yet to find it, but I haven't looked very hard. ....and it's possible that something just broke and a part failed. And if it did, DJI should pick up all the costs. I'm getting that they didn't say as much
DJI basically has not responded about the crash. The only thing they are interested in is repair and money. Even though I tried to tell the guy my entire story on what happened, I wasn't talking to a sympathetic ear. All he told me to do was write back to the person that sent me the repair invoice. They have not answered any of my concerns. Perhaps I will try again tomorrow and call them as soon as they open.
 
agree. Just make sure mod value is around 1500 before every flight. Learn to shift to atti mode and fly it from there. I know you have to be ready and do it quick. That's when knowing how to really fly a drone helps.
mod value? This I need to pay closer attention to myself! Help me understand just what mod value this means. My assumption this is located under "sensors" and refers to the "compass" mod value. Would I be correct? If this value is less than "1400" or more than "1600" is just a compass calibration needed, or do I need also do an "imu" calibration as well? many thanks, jerry
 
mod value? This I need to pay closer attention to myself! Help me understand just what mod value this means. My assumption this is located under "sensors" and refers to the "compass" mod value. Would I be correct? If this value is less than "1400" or more than "1600" is just a compass calibration needed, or do I need also do an "imu" calibration as well? many thanks, jerry
Mod value will vary. The range will vary. Try to get close to 1500 on your calibration. IMU calibration needs to be done once after you upgrade firmware. I don't know how its calculated but it has to do with the right X,Y,Z coordinates
 
So here's what the dammed battery looks like these days.

8122825_IMG_7998.jpg.jpeg
 
It's interesting that very few mention the IMU (Inertial Measurement Unit) for possible failure when fly-aways occur. Everyone seems to be quick to blame Compass calibration, which may be the cause, but not the only possibility. It would seem an IMU failure could logically be a possible cause of fly-aways. If it fails the sensor can indicate to the system the craft is moving, when it's actually not. So to counter the false indication, the craft leans in the direction to compensate for the false reading, resulting in the craft flying away. It would be interesting to hear from an engineer that designs these nav systems. That would be a good seminar to attend, if someone could put that together at a Drone convention somewhere.
 
It's interesting that very few mention the IMU (Inertial Measurement Unit) for possible failure when fly-aways occur. Everyone seems to be quick to blame Compass calibration, which may be the cause, but not the only possibility. It would seem an IMU failure could logically be a possible cause of fly-aways. If it fails the sensor can indicate to the system the craft is moving, when it's actually not. So to counter the false indication, the craft leans in the direction to compensate for the false reading, resulting in the craft flying away. It would be interesting to hear from an engineer that designs these nav systems. That would be a good seminar to attend, if someone could put that together at a Drone convention somewhere.

You would think the software engineers would have algorithms to cross check readings with, let's say the satellites, to indicate that one shows movement, when the other doesn't. If they don't match, then all forward movement of the craft should cease due to the contradictions in readings. Makes sense... no?
 
What I'm thinking is what if it hit a person instead of a wall! I have not flown mine yet. I'm choosing an open space first time
 

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