Newbie Question Alert!!!

[Suhail78]

Hey guys,

Had my P4 for about 4 days now, and i'm loving this this thing. just a couple questions for the more experienced among us....

I stumbled across this article.....

10 things that could save your drone | Paul Joy – Freelance Filmmaker

Now everything I've read up until this point indicates that we should calibrate the compass before every flight, which i have been doing. So i was wondering what "the more experienced among us" think about the 1st point this guy makes in his article, "1. Know when and when NOT to calibrate the compass"

Can some of you share your opinions of this?

Next....Point 2 he makes..."2. Know when and when NOT to calibrate the IMU"
As far as i can tell, the P4 automatically calibrates the IMU when i power it on. Is this correct?

lastly point 6 he makes...."6. Switch tablets and phones to Airplane mode"

i've read that leaving wi-fi on is okay (my ipad is wi-fi only, but i'd like to tether it to my iphone's data connection for testing out the live streaming to facebook or youtube.....and i think that happens via a combination of wi-fi and blue-tooth)

those are my only dumb questions for right now...........oh wait! one more...sorry!

Yesterday i was in a new location i never flew before, and was trying to calibrate my compass, and was getting a message that there is magnetic interference or something of that sort....happened a few times, and then i realized it could be my apple watch band b/c it has a magnetic clasp. After i took the watch off, it seemed to calibrate just fine, but i'm pretty sure it worked the other times i've done the calibration wearing the watch. Maybe i was just holding it differently this most recent time, but not sure?

I'd love to hear some thoughts and get some advise on these topics! Appreciate it, this forum is awesome.

here's a shot from my flight yesterday evening!!

 

[msinger]

1. Know when and when NOT to calibrate the compass

Check out this thread for the best advice on this topic.

2. Know when and when NOT to calibrate the IMU"
As far as i can tell, the P4 automatically calibrates the IMU when i power it on. Is this correct?

The IMU is not automatically calibrated. You should calibrate it in DJI GO when you first receive your Phantom, after installing new firmware, or if you ever crash/drop your Phantom. Before starting the calibration, make sure your Phantom is sitting on a level surface (check it with a level). And, make sure nothing disturbs it while the calibration is running.

6. Switch tablets and phones to Airplane mode

People normally do this to conserve resources on their mobile device. It often makes DJI GO run better on slower devices.

 

[Suhail78]

Thanks for the info sir!!!!

 

[Suhail78]

I think i saw it say "initializing IMU" and thought that was it doing the calibration.

 

[msinger]

Right -- you will see that when your Phantom is starting up. It's not calibrating the IMU at that time though.

 

[Great_Lakes]

Since the beginning mine always said "Warming up", but the last time I turned it on it did say "IMU initializing". The camera and gimble were off, maybe that's why.

 

[ussvertigo]

A magnet on your watch could be affecting the compass, two legs don't have the sensors so that may explain why it may not mattered on that occasion, and there is always that rare occasion some type of metal may be buried right under your cal spot, just move over a few feet. But I would take the watch off if it has a magnet in it. Also a few miles form last comp cal probably won't matter, if you understand the earths lines of magnetic field variances, and that's what the compass cal will take in account when the distance is great enough. What that is I have no idea but it can't hurt to cal at every new location, but I don't do a cal unless I change locations.

 

[Suhail78]

Tha k you for such a detailed answer, i really appreciate that! Last couple times i flew i took the watch off and things worked out


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[John Locke]

Now everything I've read up until this point indicates that we should calibrate the compass before every flight, which i have been doing. So i was wondering what "the more experienced among us" think about the 1st point this guy makes in his article, "1. Know when and when NOT to calibrate the compass"

It's not necessary to calibrate your compass before every flight, even though I've seen DJI marketing state otherwise. It's simply not necessary. If you fly more than 100mi from the last calibration, then it's a good idea to calibrate. I actually only calibrate if I move more than 100mi East or West. If I travel north 400mi, I don't calibrate, but that's just me. Logically it doesn't make sense, and it's always been fine, no compass problems. In fact, my P4 seems to be way more stable on compass integrity than my P3P, likely due to the dual compass. However, just like the routine of checking the compass MOD values on the P3P before flight, I'm always checking the compass status in the P4 Go app before take-off. It's a habit, but I've never seen an anomaly in the P4 compass status.

 

[Suhail78]

It's not necessary to calibrate your compass before every flight, even though I've seen DJI marketing state otherwise. It's simply not necessary. If you fly more than 100mi from the last calibration, then it's a good idea to calibrate. I actually only calibrate if I move more than 100mi East or West. If I travel north 400mi, I don't calibrate, but that's just me. Logically it doesn't make sense, and it's always been fine, no compass problems. In fact, my P4 seems to be way more stable on compass integrity than my P3P, likely due to the dual compass. However, just like the routine of checking the compass MOD values on the P3P before flight, I'm always checking the compass status in the P4 Go app before take-off. It's a habit, but I've never seen an anomaly in the P4 compass status.

Thanks for the reply, I've only had my P4 since Sunday, have flown it every day, and doing a calibration, i wont calibrate next flight and see how she performs! Thanks again buddy!


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[MarkNH]

I calibrated my P4 compass twice in 40 flights. The only reason I did a second one was because of an update. I also have a P2V+ that I rarely did the compass calibration on. Never had any problems.

 

[Great_Lakes]

I calibrated my P4 compass twice in 40 flights. The only reason I did a second one was because of an update. I also have a P2V+ that I rarely did the compass calibration on. Never had any problems.

Same here.

 

[John Locke]

Thanks for the reply, I've only had my P4 since Sunday, have flown it every day, and doing a calibration, i wont calibrate next flight and see how she performs! Thanks again buddy!


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Welcome to the P4 crowd! You'll have a good time. Being that you're new to P4, it will be good to practice flying in ATTI mode in an open field. If the compass were to ever go wacky, you'll be put into ATTI mode, and it's good to be familiar with the flight characteristics of ATTI if that were to happen. Basically ATTI doesn't hold your horizontal position, only the vertical position. So if it's windy, the craft will drift. You have to compensate for that with the sticks.

That said, I've never had my P4 go wacky with the compass like the P3 does on rare occasions. So you'll likely never have to deal with it, unless you get in a strange magnetic area that confuses the craft compass. It can happen, so be ready. Also, if you ever lose GPS signal, such as going under a cement bridge, you'll be put into ATTI mode, so be ready for that possibility. Practice with ATTI in an open field, it's fun. Many pro videographers prefer ATTI flight to minimize any sudden stops from the DJI braking, inherent in the P mode.

 

[XJoeyX]

Welcome!

Something else to consider. Never take off, or calibrate a compass, on a concrete slab, sidewalk, driveway, etc. There is a LOT of reinforcing bar (rebar) in almost anything made of concrete. This can negatively affect your compass. If you must take off from a man-made surface, you would be safer taking off from an asphalt road, as the asphalt is generally just compacted base material under the paving (no rebar). I prefer taking off from a grass field, but if you don't have some sort of launch pad, this can cause tip-overs on landing, so just be careful.

Just some thoughts,
~Joey

 

[Suhail78]

Welcome to the P4 crowd! You'll have a good time. Being that you're new to P4, it will be good to practice flying in ATTI mode in an open field. If the compass were to ever go wacky, you'll be put into ATTI mode, and it's good to be familiar with the flight characteristics of ATTI if that were to happen. Basically ATTI doesn't hold your horizontal position, only the vertical position. So if it's windy, the craft will drift. You have to compensate for that with the sticks.

That said, I've never had my P4 go wacky with the compass like the P3 does on rare occasions. So you'll likely never have to deal with it, unless you get in a strange magnetic area that confuses the craft compass. It can happen, so be ready. Also, if you ever lose GPS signal, such as going under a cement bridge, you'll be put into ATTI mode, so be ready for that possibility. Practice with ATTI in an open field, it's fun. Many pro videographers prefer ATTI flight to minimize any sudden stops from the DJI braking, inherent in the P mode.

John, i really really appreciate your advice, and plan on taking it! Im gonna try to head out to a field tomorrow if it doesn't rain (its supposed to...), and give atti mode a go! Thanks again sir!


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[Suhail78]

Welcome!

Something else to consider. Never take off, or calibrate a compass, on a concrete slab, sidewalk, driveway, etc. There is a LOT of reinforcing bar (rebar) in almost anything made of concrete. This can negatively affect your compass. If you must take off from a man-made surface, you would be safer taking off from an asphalt road, as the asphalt is generally just compacted base material under the paving (no rebar). I prefer taking off from a grass field, but if you don't have some sort of launch pad, this can cause tip-overs on landing, so just be careful.

Just some thoughts,
~Joey

Hey thanks for that tip! So far I've only flown off grass surfaces, but thats definitely something good to know!! Appreciate it!!


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[KingDad1985]

I also just bought my P4 and only have I battery ran through it. I also have a p3a well it's my wife's now which I've flown 3 Batts through so I'm pretty new to all this. Thank OP for posting this thread and thanks to everyone for all the great feed back. Since joining this forum everyone has been super nice and super helpful. Great community we have here.

 

[ussvertigo]

ATTI is fun and helps hone your skills, I tell people it acts like a hockey puck on ice.

 

[Suhail78]

ATTI is fun and helps hone your skills, I tell people it acts like a hockey puck on ice.

I was playing around with it in the flight simulator on the DJI Go app today, just wanted to get a feel for it before i took it out. Was setting different wind speeds in the simulator just to see how it would behave. Its raining here today, so once the weather breaks ill give it a go in an open field! Thanks for the response, much appreciated sir.


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[XJoeyX]

Hey thanks for that tip! So far I've only flown off grass surfaces, but thats definitely something good to know!! Appreciate it!!

Any time! we are all here to help each other!
~Joey