davidmartingraf Posted at 2018-5-6 10:13
My pleasure. I've only flown a few times at my sister's house because whenever I do the DJI GO 4 Application sometimes continues prompting me to re-calibrate the compass and IMU. I once calibrated successfully however as soon as I got up in the air the Spark was reading compass error so I quickly landed. I think this is typical to the fact that that area has new construction with metal in the ground underneath? With that said, I'm always cognizant when flying in new areas to calibrate the compass because you want to ensure that the drone can RTH.

Thank you for the update. So I will be watching for any Concrete Rebar and Interferance in the Area.

DMX_MT Posted at 2018-5-6 10:22
Thank you for the update. So I will be watching for any Concrete Rebar and Interferance in the Area.

That's pretty much what I do and it always helps to continue watching for, and reading, these posts to see what kinds of trends other people tend to encounter - this way you're always best prepared for every time you fly.

DMX_MLT Posted at 2018-5-6 05:22
Hello Ram !

When you say Sport Mode it is like ATTI Mode ?

Hi Darryl
In sports mode GPS will work but the front sensors and some of the options ( ie quick shot) will be disabled. So take extreme care when you fly in sports mode.
You also take note that it will reduce the flight time (use more power) and breaking distance will be hugely increased.

It is not recommend to fly in sports mode unless you are comfortable with the controls and can manage speeds upto 50km/h+.
But it’s fun to fly in sports mode. I always fly in sports mode unless I am recording video.

You have to fly in VLOS always irrespective of the mode you are using.

Ram-UK Posted at 2018-5-6 10:50
Hi Darryl
In sports mode GPS will work but the front sensors and some of the options ( ie quick shot) will be disabled. So take extreme care when you fly in sports mode.
You also take note that it will reduce the flight time (use more power) and breaking distance will be hugely increased.

Thank you Ram,

I will try Sports mode, after I get some confidence with the Drone.

I heard you can use it instead of RTH as I saw a comparison video, Sports Mode arrived before so less battery was used. I am not planning to do long distances. I will keep my Spark at VLOS as your suggested, and also to obey the rules we have here.

Re the RTH, do you suggest setting the Batteries Low Level at 30% or 25% please ? When the Battery is low the Spark will turn on RTH, which you can cancel anytime. Right ? When RTH is cancelled is it best to come back with RTH or Sportsmode like I told you ?

Thank you !

DMX_MLT Posted at 2018-5-6 05:16
Msinger, when the Spark goes ATTI Mode and may cause a Flyaway, it is because - ?

1) The GPS will not Function so the Drone will be Depending on the IMU / Barometer (Barometer for Establishing Height?) only ? So it may Drift Away with Wind right ?

None of those.

If the Spark auto switches to ATTI mode due to a compass issue, you'll likely have trouble controlling it since the direction the flight controller thinks the Spark is facing is not the actual direction it's facing. So, you might attempt to steer it straight ahead and it will turn to the right instead (for example). The difference in those two headings usually changes as the Spark continues to fly too (causing an arc-like motion that can be seen in some flight logs).

That's why I'm suggesting you land in a situation like this. Down is always down, so the heading disagreement won't affect that path of travel.

msinger Posted at 2018-5-6 11:33
None of those.

If the Spark auto switches to ATTI mode due to a compass issue, you'll likely have trouble controlling it since the direction the flight controller thinks the Spark is facing is not the actual direction it's facing. So, you might attempt to steer it straight ahead and it will turn to the right instead (for example). The difference in those two headings usually changes as the Spark continues to fly too (causing an arc-like motion that can be seen in some flight logs).

Very good suggestion.

Thats why Line of Sight is important right ?

Please Msinger can you tell me how I should now when I have the mode switched to ATTI will this be displayed on the phone as a Particular Error which I should be watching for - Eg. ''Interference Switching to ATTI.''

Are there any other Errors which can cause the Spark to ATTI ? Maybe GPS lost ? That isnt so dangerous right ? as the Controller will still Obey ?

When the Controller loses Connection with the Spark and returns home, is it best to let it return via RTH ? Or if it makes connection again I do Cancel and return home manually ? Or I ignore everything and I continue Flying ?

DMX_MT Posted at 2018-5-6 14:30
Very good suggestion.

Thats why Line of Sight is important right ?

The DJI GO app will tell you if the Spark auto switches to ATTI mode.

Poor and/or no GPS connection is the other most common reason the Spark will auto switch to ATTI mode. In that case, the Spark will drift with the wind if the sticks are in the center positions. When you're manning the sticks, the Spark will respond just like it normally does (since it's not being affected by magnetic interference).

If the remote controller signal is lost and the Spark auto returns home, you could cancel RTH by pressing the RTH button on the remote controller once the Spark is back in sight. That's what I normally do in that case since I prefer to have total control when the Spark is landing.

I never did a compass calib. I have the Spark for a year now.
When the app shows interference, I shut down everything and move to another place. I check the sensors and they are all good to fly.

msinger Posted at 2018-5-6 16:56
The DJI GO app will tell you if the Spark auto switches to ATTI mode.

Poor and/or no GPS connection is the other most common reason the Spark will auto switch to ATTI mode. In that case, the Spark will drift with the wind if the sticks are in the center positions. When you're manning the sticks, the Spark will respond just like it normally does (since it's not being affected by magnetic interference).

Thank you Msinger,

If the Spark loses connection or has poor with the GPS, I will manually fly the spark back home. There will be no need to panic right ?

I will only use RTH as you said, and in Emergency Situations only. I will fly back using Sportsmode.

Does the DJI Go4 prompt you a different Error when -

1 Switching to ATTI because of Lost GPS Signal ?

2 Switching to ATTI because of Large Interference and leading to Compass Error ?

In another situation, I believe the Spark wont switch to ATTI Mode if it loses connection with the Remote & Phone, it will just wait few seconds, if connection is still lost, the Spark will Automatically Trigger RTH and come Back right ? During the RTH I can gain connection again with the Spark via the Controller and Phone  Automatically, I dont need to do anything ?
Most likely I wont have this issue as I am prepared to keep follwing the VLOS Rule.

Jos A Posted at 2018-5-6 22:23
I never did a compass calib. I have the Spark for a year now.
When the app shows interference, I shut down everything and move to another place. I check the sensors and they are all good to fly.

Thank you Jos A.

DMX_MT Posted at 2018-5-7 01:25
Thank you Msinger,

If the Spark loses connection or has poor with the GPS, I will manually fly the spark back home. There will be no need to panic right ?

As long as the remote controller is connected to the Spark, you will be able to manually fly it back to the home point. It would also be helpful if you keep the Spark within VLOS so you can easily see it with your eyes.

The DJI GO app will always show you when the Spark is flying in ATTI mode. It will also pop up error messages on the screen mid-flight. Keep an eye on the DJI GO app as you fly so you know what's going on.

The Spark can switch to ATTI mode before or after the remote controller signal is lost. If in ATTI mode and the remote controller signal is lost, it will auto land at its current location after three seconds. It won't be able to return to the home point since the GPS data is not used while flying in ATTI mode.

msinger Posted at 2018-5-7 05:07
As long as the remote controller is connected to the Spark, you will be able to manually fly it back to the home point. It would also be helpful if you keep the Spark within VLOS so you can easily see it with your eyes.

The DJI GO app will always show you when the Spark is flying in ATTI mode. It will also pop up error messages on the screen mid-flight. Keep an eye on the DJI GO app as you fly so you know what's going on.

So that will be a problem if you are on Water !
What shall I do if its in ATTI mode and it loses connection msinger ?

What are the Worst errors I can get ? Maybe you have a good video for me to watch and learn with examples please ?

BTW Thanks for all this, I am taking notes in the mean time as you really explain them easily to understand !

DMX_MT Posted at 2018-5-7 05:15
So that will be a problem if you are on Water !
What shall I do if its in ATTI mode and it loses connection msinger ?

If the remote controller signal is lost and it lands in the water? The first thing you'll want to do is hope you remembered to take swimming lessons.

msinger Posted at 2018-5-7 05:28
If the remote controller signal is lost and it lands in the water? The first thing you'll want to do is hope you remembered to take swimming lessons.

Hehehe ! I am laughing now with your Comment

Malta is an Island in the Mediterranean and most of us know how to swim, but at that moment with I will drown with a Heart Attack !

msinger Posted at 2018-5-7 05:28
If the remote controller signal is lost and it lands in the water? The first thing you'll want to do is hope you remembered to take swimming lessons.

Joking apart msinger, does it easily go to ATTI and Disconnect from Remote ?

What can I do to prevent it ? Thats why I think its so risky to fly very far distances right ?

If you have a Mavic Pro, will these disconnection issue be far less ? As I hear that Mavic have Occusync, Longer Range and also 2 IMu / 2 Compass / 2 GPS and back up just in case something happens).

I think the Mavic Air is only WIFI not like Mavic Pro right ?

DMX_MT Posted at 2018-5-7 05:53
Joking apart msinger, does it easily go to ATTI and Disconnect from Remote ?

What can I do to prevent it ? Thats why I think its so risky to fly very far distances right ?

The remote controller most often disconnects when it's out of range or an obstacle comes in between the Spark and remote controller. Since you said you're only going to fly VLOS, that shouldn't be an issue.

msinger Posted at 2018-5-7 07:03
The remote controller most often disconnects when it's out of range or an obstacle comes in between the Spark and remote controller. Since you said you're only going to fly VLOS, that shouldn't be an issue.

Thank you Msinger. When you say out of range you mean doing those long distance tests ?

If it disconnects behind some trees, there wont be water and sea, so that wont be a problem.

I think this Problem that it loses GPS + loses Remote connection is not a usual problem right ?

With DJI Care Refresh, will you be covered if the Drone has GPS Error, turns to ATTI, and then Disconnects from the Remote ?

DMX_MT Posted at 2018-5-7 07:41
Thank you Msinger. When you say out of range you mean doing those long distance tests ?

If it disconnects behind some trees, there wont be water and sea, so that wont be a problem.

By out of range, I mean the remote controller cannot communicate with the Spark if it's too far away.

GPS loss + loss of remote controller signal should not be a common event. If it is common, you're likely doing something wrong.

Check out the DJI Care Refresh Terms of Service at the following link for more details on what it covers:

https://www.dji.com/service/djicare-refresh/info

msinger Posted at 2018-5-7 07:58
By out of range, I mean the remote controller cannot communicate with the Spark if it's too far away.

GPS loss + loss of remote controller signal should not be a common event. If it is common, you're likely doing something wrong.

Will certainly do. Thanks MS !

I bookmarked the Page. Thank you !

I used to do a compass calibration before every flight (the first 3 times). but now I just check the sensors in the app and won't start flying unless my home point has been updated.

Racingboy Posted at 2018-5-8 00:32
I used to do a compass calibration before every flight (the first 3 times). but now I just check the sensors in the app and won't start flying unless my home point has been updated.

Thanks for your advice RB.

I never used to, but....every time i travel overseas and back, i recalibrate everything possible, after the nightmare from my last trip >

This is from DJI...

Hi, I fly backyard... same spot over/over... Go4 asked for a caibration today.... NP!  I'm good in this spot till I fly down the road tomorrow... Then I'll manually force a re-calibration if the auto re-cal alert doesn't prompt me. New take-off site... new re-calc.

DMX_MT Posted at 2018-5-6 11:14
Thank you Ram,

I will try Sports mode, after I get some confidence with the Drone.

Sports mode is faster and sometimes needed to fly back against the wind if you get into trouble but uses more energy.
I haven't done any comparisons between normal and sports mode battery usage. But I have done up to about 4220m with one battery in sports mode.

I have set my Battery low level to 30% it's better to be safe than sorry.

Ram-UK Posted at 2018-5-9 04:47
Sports mode is faster and sometimes needed to fly back against the wind if you get into trouble but uses more energy.
I haven't done any comparisons between normal and sports mode battery usage. But I have done up to about 4220m with one battery in sports mode.

Thanks Ram !

Infact I was thinking to ask about suggested Battery % before the RTH Triggers. I agree with you 30% is ideal for me too.

Also as you say Sportsmode is better to come back. I saw a video in which Sportmode makes it with less battery consumption as it travels faster. I wish to make my flybacks manually, as many have suggested this way.

Thanks Ram ! Good day Buddy !

Ram-UK Posted at 2018-5-9 04:47
Sports mode is faster and sometimes needed to fly back against the wind if you get into trouble but uses more energy.
I haven't done any comparisons between normal and sports mode battery usage. But I have done up to about 4220m with one battery in sports mode.

Here you go Ram -

In this situation he travelled to 2.5KM and turned back at 58% Battery.


Wiht Manual Sportsmode at 31% he arrived Home. Touch down at 22%.

With RTH touch down is at 15%.


So this means RTH consumed 7% more than Sportsmode Manual Return @ 2.5 Km.

Aurelian (Spark) Posted at 2018-5-5 12:50
I do what the manual says: Compass Calibration only when Prompted by DJI GO4 App

I used the same guide until recently.  DJI updated or changed their process, which I believe was highlighted in one of their posts and has been added to some of the newer manuals.  

They suggest recalibration when you fly from a different location than your last flight.   So if you drive to a different park instead of flying from home, they suggest compass recalibration before taking off.

Makes sense when you consider that the earth isn't flat (really!) and the magnetic interferences can vary by location.  Same precautions, stay away from metal, magnetic sources, anyone with a beard :-)

WebParrot Posted at 2018-5-9 06:00
I used the same guide until recently.  DJI updated or changed their process, which I believe was highlighted in one of their posts and has been added to some of the newer manuals.  

They suggest recalibration when you fly from a different location than your last flight.   So if you drive to a different park instead of flying from home, they suggest compass recalibration before taking off.

It's not a problem for me to calibrate the compas before I take off. If you do it in optimal conditions, it takes less than a minute and you can save yourself a lot of problems. Prevention is better than cure.

Hi,

I would calibrate after changing location by several hundred kilometres due to changing magnetic declination.
While Spark manual does not say that - here is a clip from Mavic Air manual.
I don't think that Mavic Air compass is weaker (if anything, it is more robust than Spark's) but DJI does recommend to calibrate it if moving long distances or if the AC has not been flown for some time.



For Spark, DJI is cautious because bad compass calibration may be worse than no compass calibration. And Spark is marketed for beginners.
However, if you do calibration right and in right place with no interference, there is no reason why it should hurt. It may only help.

Mirek

Since I see it over and over on this forum.
There are limitation to discussing who believes what and what the manual says.
You can see and appreciate that everybody has some opinion but it is hard to determine what is actually right.
Yes – you can rely on experience and figure out that if compass worked for you so far with just one calibration, it will work forever. Well – this is just wishful thinking. You may be right or you may, one day, be sorely surprised. This is not black and white proposition. Read on …

The key is to understand how electronic magnetometers works. Based on that knowledge you can form educated opinions. And once you know it, you will know what risk, if any, you are running by calibrating or not calibrating your compass.

Quick compass primer.

It is vital that drone knows which way is north. Entire calculation of flight path depends on co-operation between magnetometer, gyroscope, accelerometer and GPS positioning receiver. Magnetometer is key – it tells drone exactly where the magnetic north is and which way – geographically – the drone is pointing (calculated based on magnetic declination of its physical location as per GPS).

Electronic magnetometers in drones operate in three axis. They have to, since drone’s attitude has three axis and Earth electromagnetic field has three axis.
When you calibrate drones magnetometer by turning drone around – it measures Earths electromagnetic field in all directions, it figures disturbances caused by ferromagnetic materials in drone itself and in drone’s vicinity and, based on this information acquired from various directions it does quite complex calculations to determine all offset errors (hard/soft iron, zero bias, scale factor, non-orthogonal, misalignment etc.) and figure out exactly where magnetic north is.

So what can happen with time or travel to threw this calibration off?

You can pass through strong magnetic fields which will skew drone’s magnetic sensors prompting necessity for recalibration.
Magnetic fields can also magnetize internal parts of your drone which will have direct effect on magnetometer sensors.
Magnetic properties of materials change with time as well.

But what is much more important is that Earth’s Magnetic field is distorted in various places. It is not just South-North. It has vertical inclination which may be different in different locations. In may be skewed and affected by geological features. There are many reasons for it. If you travel between far away places, the chances are that the three-dimensional features of the Earth’s magnetic field will be different and that its strength will be different. If your magnetometer is calibrated in one location, it may not show correct magnetic North due to these differences – it needs to be recalibrated again.

Granted – in many (most) situations Spark’s controller will sense that something is not quite right and give you a warning asking to re-calibrate.
But… how many times did you see Spark’s issues on this forum which are caused by wrong readings of sensors, errors in firmware etc? Would you always, unequivocally, trust that Spark will discover all inconsistencies which may necessitate magnetometer re-calibration? Maybe you would. But I will err on the safe side and re-calibrate when I understand that re-calibration may be required even though Spark’s sensors are telling me that all is kosher.

Mirek

msinger Posted at 2018-5-5 11:36
There's no need to calibrate the compass before each flight. However, if you choose to do it, you won't hurt anything. For best practices, check out the Spark Compass Calibration Guide.

For your pre-flight, it would be better to do this instead:

I noticed the radar in lower left corner was 180 degrees off, so I calibrated the phone, not the drone and acquired near perfect alignment. I did not notice the ac alignment in the map itself unfortunately. So is the map's ac orientation then rely on the ac orientation, and the radar, the phones/tablet internal compass?

Its hard to tell exactly when I calibrate the compass.
Yesterday before flight (same location) I checked the compass parameters and the bar was yellow. DJI GO didnt prompt to calibrate the compass. I changed location and the bar still yellow so I decided to calibrate the compass. After that the bar got stabilized on green with low numbers then I was free to fly.

fansa7dc5944 Posted at 2018-5-5 22:01
Compass calibration may not guarantee that your Aircraft will not fly away. One common serious mistake the pilot did was hitting the RTH in hope for the aircraft to return to the takeoff location by itsself, which it will not ever. Do the calibration is good but as stated in the manual, only when you are asked to do. First try moving the aircraft to different location. If the compass calibration message still appear then try another. Let compass calibration be the final one.

I agree!
If you always calibrate before you take off, it will soon become a routine and you will not pay much attention and you will not notice it if you calibrate in the wrong place. You can use a constant calibration to enter a random error in the control.
"If something works well it does not have to be repaired" is a good saying and true.

You probably know this DJI too, and that's why you wrote in this manual that you do not have to calibrate unless the software detects a problem and asks you to do so.

I do not think the flyaway can be prevented, though many people believe it.

It is important to observe the compass behavior and state of the compass (settings of sensor status) and if you experience something abnormal, you need to stop flying immediately.

BrilhasMuito Posted at 2018-6-29 15:49
Its hard to tell exactly when I calibrate the compass.
Yesterday before flight (same location) I checked the compass parameters and the bar was yellow. DJI GO didnt prompt to calibrate the compass. I changed location and the bar still yellow so I decided to calibrate the compass. After that the bar got stabilized on green with low numbers then I was free to fly.

So did not ask the app., but did you calibrate it where there was a possible interference?
You can also do a bad calibration and fly away to a place where there is no trouble and then the compass starts to point in another direction that IMU can not handle (does not understand) and Yaw error, compass error, "Atti" mode and flyaway ....

Jakab Gipsz Posted at 2018-6-29 16:09
So did not ask the app., but did you calibrate it where there was a possible interference?
You can also do a bad calibration and fly away to a place where there is no trouble and then the compass starts to point in another direction that IMU can not handle (does not understand) and Yaw error, compass error, "Atti" mode and flyaway ....

I made sure it wasnt the location. I always fly there so I know the place is free of interference.
I moved location 3 times and the bar kept yellow therefore I recalibrated it.
If you don't mind flying with a yellow bar on your compass parameters you are free to go but I'd rather see a green bar before taking off.

Mirek6 Posted at 2018-6-29 12:17
Since I see it over and over on this forum.
There are limitation to discussing who believes what and what the manual says.
You can see and appreciate that everybody has some opinion but it is hard to determine what is actually right.

Since the changes in the gentle field are not so dense, it is enough to calibrate if you travel further 50Km.
Due to magnetism and time change, if it was not switched on for 30 days, it should be recalibrated.

These manuals are engineered by the engineers who designed the navigation system. I would not argue with them.

If it indicates interference, it is wise to calibrate at that location?

Therefore, once it is calibrated and does not indicate a fault and you flew it, you do not have to replace this correct and proven setting with an uncertain one.

This is my chrystal clear logic and not a sacred writing!

Jakab Gipsz Posted at 2018-6-29 16:31
Since the changes in the gentle field are not so dense, it is enough to calibrate if you travel further 50Km.
Due to magnetism and time change, if it was not switched on for 3 months, it should be recalibrated.

If you keep moving location and the bar keeps showing interference usually means its not the location its the AC that needs a compass calibration. It's not wise to calibrate it in a busy enviroment.
Obviously you gotta make sure its a interference free enviroment. It's all about observation. It's up to you to decide if the calibration is needed and if the enviroment is safe to calibrate it.

Mirek6 Posted at 2018-6-29 08:41
Hi,

I would calibrate after changing location by several hundred kilometres due to changing magnetic declination.

Yes, if it is calibrated in the right place!
But people are calibrated instantly when there is interference from the app. even where there is interference. And here in the board I always read that you calibrate before every take-off, because that can only be good!
It's nonsense!

A precision accessory for the compass is Drones, with just enough precision (unshakeable, twisted) in a confusing environment.

Therefore, if not necessarily, you should not poke.

(This is my opinion in my logic and technical knowledge)

Jakab Gipsz Posted at 2018-6-29 16:44
Yes, if it is calibrated in the right place!
But people are calibrated instantly when there is interference from the app. even where there is interference. And here in the board I always read that you calibrate before every take-off, because that can only be good!
It's nonsense!

Usually when its prompted moving the AC a few meters is enough to avoid the interference. But sometimes its not the enviroment at all. As I said its all about observation and common sense.