So I was flying my spark for the 2nd time last night. Things went very well.. This thing is so impressive. A few times it lost signal, but only momentarily.  Scared me, but I still had control it looked like.   Other than that, it was fine.  It led me to want to know, what happens if it does lose connection.  I use the OTG cable and remote,  and have my wifi off so I'm soley using the RC connection.

So if it drops, does the spark just sit and hover?  Would I utilize the pause button or what exactly is that used for.  Will it just go in atti mode which is manual mode right?

Thanks in advance!

Your drone will initate RTH (return to home) when conection is lost. If it loses gps, it goes into ATTI mode and will get pushed around by the wind. The pause button used to stop auto flight during quick shots

Hi,

see https://forum.dji.com/thread-151418-1-1.html

Enjoy and have fun with your drone.
Cheers
JJB

@ JJB

What does a Pre-Flight Checklist got to do with losing GPS ?

Pre-Flight Checklist is done before a Flight to check everything is correct and the Drone is good for Flying, eg. Compass Check, Imu Check, Satellites Check, Control Charged, Spark Charged, Propellers Ok, Battery in Lock Position etc... etc...

I don't understand you dude. Try reading the question before typing.

JJBspark Posted at 2018-6-14 04:28
Hi,

see https://forum.dji.com/thread-151418-1-1.html

@ djiuser_1PTTfOBxLfMS

Greg Glasson is right.

When you Lose GPS Signal, the Spark will enter ATTI Mode.

Here you will still have control of the Spark, but the Spark won't have a GPS Signal to hold positioning. It won't force itself back to the last co-ordinates, so with even the slight wind it may start drifting away. Also if you do movements with the Controller, it will not AutoBrake but continue Drifting.

Follow the Link to see many Video Tutorials on GPS Signals / Compass Errors / IMU Errors etc..... https://forum.dji.com/thread-151297-1-1.html

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Now @ JJB -

What does a Pre-Flight Checklist got to do with ATTI Mode, JJB ??
Making routine checks as Pre-Flight Checklist is Important, but that was not the question this guy is asking. He wants to know - ''What happens when GPS is lost'', I think the language barrier is the problem right ?

Ahhh you are trying to copy me to become Famous !
Haha ! Get Creative dude..

DMX_MT Posted at 2018-6-14 05:55
@ JJB

What does a Pre-Flight Checklist got to do with losing GPS ?

Hi,

Would be great if you not react on my comments, just because you dont like me for some reason.

This user ask questions wich make clear that he doesnt have much knowlegde. My first line in my checklist is RTFM and understand it! So that`s why i refer to a checklist.
Mayby hard to understand if you are full of negative emotions about me.

But i must say you`d normally post good posts, not this one i`m afraid.

Cheers and good luck.

Btw, i recommend the book ISBN 978-0-06-114789-0 ; you should read this one.
Cheers
JJB

JJBspark Posted at 2018-6-14 06:39
Hi,

Would be great if you not react on my comments, just because you dont like me for some reason.

Hello JJB,


You were the first to light the Spark and made fun of me, on the other posts, though I was cool about it.

Is it a problem if I criticise you when I don't agree with some of your comments ? Do you consider yourself such a Big Wig these days ?

Comeone JJB, don't need to make such a Fuss Dude ! Don't create a storm in a teacup just when someone doesn't agree with you.

I only said the Truth that this guy wanted to know about ATTI not an Advert about your Pre-Flight Checklist.

Hallmark007 has done a really good one last year, so this is all Old News. I even linked it in my Forum as hes a Charasmathic Guy, you should learn from him.

Try to start learning from criticism JJB. Seriously, Start accepting opinions, Stop acting so Sad and Boring.

I suggest your read the Fairy Tale of 'HUMPTY DUMPTY' . The Giant Egg that had his head grew so BIG and he climbed so high, that the Fall was Devastating for Him. I suggested a Fairy Tale as your Avatar is a Cartoon...

Also most of the message you typed can be applied to yourself.


Cheers and Goodluck Mr.Hans ! You can start contacting your rugrat friends to downvote me as usual, its ok.

This is why I told you in the Previous Post that Lately you think you are a Genius and above everyone else.

You are too big headed Hans, you need to start listening to others and share you knowledge without Bluff.

We are here to learn from each other, there are times when some agree with us and other where they disagree.

Sending Private Messages calling me an Idiot, doesn't help, just for as I didn't agree with you.

Please be nice.

I see many storms in a teacup on this forum but none by JJB ;)

Just relax and for Pete's sake fly your drones finally.

JimboHUN Posted at 2018-6-14 09:46
I see many storms in a teacup on this forum but none by JJB ;)

Just relax and for Pete's sake fly your drones finally.

Everyone has the right to express his own opinion.

I just told JJB that the subject is on GPS Loss not on a Preflight checklist, if you can read, you can understand.

Then JJB went attacking me again. If you only read parts of the comments you won't know the whole story.

Enjoy your day, DJI Hater.

djiuser_(lots of numbers here) :-),

Good for you for using OTG! I just wonder, if you are on Android device, which version of DJI GO are you using. Android DJI GO versions have multiple issues with OTG which you may not notice at first sight. Mostly lacking or wrong telemetry. Let me know please. I also use OTG (wifi failed me miserably in the past) but I am on Android. I use version 4.2.12 which is bullet proof on my LG G5.

To add to Greg and DMX_MT comments.

Yes - you can use Cancel button on RC to cancel RTH when RTH sequence is in progress.
Also, as DMX_MT pointed out, in ATTI mode your drone will not hold position and drift with wind and, even if there is no wind, it still may drift if its position in not perfectly level (and it rarely ever is for various reasons). Your manual commands through control sticks will work just fine (if you did not lose communication between drone and RC) but you need to expect a bit of "fight". You will fight the wind gusts and you will need to reverse your stick movements to stop the drone.

To explain it better - if you return your sticks to neutral position while your drone flies in P-GPS - drone will stop. This is what DMX_MT refers to as "AutoBrake". If you are in ATTI mode and you direct your drone to fly forward, when you put your sticks back to normal, it will not stop - the pure inertia will carry it in the same direction until air friction will slow its movement down. To stop - you need to momentarily reverse the sticks and send it in opposite direction. Flying in ATTI requires a bit of practice.

Good luck, read all the good advice you got from other pilots here and enjoy your Spark!

DMX_MT Posted at 2018-6-14 07:27
This is why I told you in the Previous Post that Lately you think you are a Genius and above everyone else.

You are too big headed Hans, you need to start listening to others and share you knowledge without Bluff.

see https://forum.dji.com/thread-152510-1-1.html

DMX_MT Posted at 2018-6-14 10:04
Everyone has the right to express his own opinion.

I just told JJB that the subject is on GPS Loss not on a Preflight checklist, if you can read, you can understand.

Attacking me again? who wrote #4 and #5 ?? in reaction i explained why i refer to a checklist.
If all the new flyers understand my points on the checklist than they will not ask these questions.

So your reaction is not understand by more than just me and totally misplaced

Cheers
JJB

OP - there is a difference to how the drone will react when losing GPS and losing signal - which are different.
GPS is the number of satellites being received by the drone to hold it's position in space and the signal is the transmission (WiFi) between the antenna in the RC and AC.
When the signal is lost the drone will enter a failsafe mode which is either hover, land or RTH depending on your setting within the app - this is subject to the home point being set on the map prior to take off and a strong GPS connection at the point of signal loss.
GPS loss is more serious as the drone will no longer know it's position in space and will not initiate RTH - it will enter ATTI mode which massively impacts on the gains of the drone as it becomes very effected by wind speeds making it more difficult to fly. This is why flying in visual line of sight is very important with these wifi based drones.

DMX_MT Posted at 2018-6-14 07:27
This is why I told you in the Previous Post that Lately you think you are a Genius and above everyone else.

You are too big headed Hans, you need to start listening to others and share you knowledge without Bluff.

a idiot? where in text please?

Mayby you have a IQ of 105 (how can i tell not knowing you at all), surely not an idiot i would say.
But interpreting my text as such tells more about you than me.

This will be mine last reaction on your misplaced posts to me.

Take care, have fun and
Cheers
JJB

A CW Posted at 2018-6-14 10:57
OP - there is a difference to how the drone will react when losing GPS and losing signal - which are different.
GPS is the number of satellites being received by the drone to hold it's position in space and the signal is the transmission (WiFi) between the antenna in the RC and AC.
When the signal is lost the drone will enter a failsafe mode which is either hover, land or RTH depending on your setting within the app - this is subject to the home point being set on the map prior to take off and a strong GPS connection at the point of signal loss.

A CW,

Very good advise. I would add that it is advisable to invest in antenna range boosters for wifi drones like Spark. They cost 15 bucks and are worth additional piece of mind. Spark is tiny, and even with VLOS and within short distance, it is easy to loose sight of it. If it enters ATTI and you cannot see it (even if it is within line of sight) and, on top of it you lose signal between AC and RC - you are in trouble.

While Spark range is advertised as FCC 2km VLOS - it did occasionally happen to me within 500 meters and with no obstacles between me and Spark. Fortunately my Spark never lost GPS while transmission was lost and always managed to RTH.

With boosters you extend your chances of not loosing signal and being able to fly your Spark using telemetry if it is too far away to judge in which direction it is flying. In my experience, when Spark is 100 metres or more from me, I have trouble to judge the direction which it is travelling (away or towards me). This is when telemetry and streaming video is golden. If you lose signal, Spark is a dot in the sky and, if it drops to ATTI -  well - good luck :-)

Mirek6 Posted at 2018-6-14 11:14
A CW,

Very good advise. I would add that it is advisable to invest in antenna range boosters for wifi drones like Spark. They cost 15 bucks and are worth additional piece of mind. Spark is tiny, and even with VLOS and within short distance, it is easy to loose sight of it. If it enters ATTI and you cannot see it (even if it is within line of sight) and, on top of it you lose signal between AC and RC - you are in trouble.

"In my experience, when Spark is 100 metres or more from me, I have trouble to judge the direction which it is travelling (away or towards me)."

If you cant judge "away or towards me", fly it to the right or to the left for 5 or 10 seconds!

And /or use the radar sight, if available (at a working Go4)

As long there is a connection and a "point in the air" to spot, there is a flight direction to find out.
And: A RTH via button still available.
After that, you know forward is back home ;-)

S-e-ven Posted at 2018-6-14 11:23
"In my experience, when Spark is 100 metres or more from me, I have trouble to judge the direction which it is travelling (away or towards me)."

If you cant judge "away or towards me", fly it to the right or to the left for 5 or 10 seconds!

Thanks for that insight!  yes, ofcourse press RTH will first yaw the craft towards home, than climb if needed to the RTH height. So press RTH, wait few seconds, cancel RTH and fly forward!
Thanks.

cheers
JJB

JJBspark Posted at 2018-6-14 11:29
Thanks for that insight!  yes, ofcourse press RTH will first yaw the craft towards home, than climb if needed to the RTH height. So press RTH, wait few seconds, cancel RTH and fly forward!
Thanks.

Just one more thing:
If I have no video stream, (my app is chrashing every now and then ;-), I like it better to fly home backwards !
Controls and bird moving 1:1 and not opposite directions.
Which can be important, if close to trees, ground, whatever

S-e-ven Posted at 2018-6-14 11:23
"In my experience, when Spark is 100 metres or more from me, I have trouble to judge the direction which it is travelling (away or towards me)."

If you cant judge "away or towards me", fly it to the right or to the left for 5 or 10 seconds!

You know, this right/left tip is really good. I did not think about it since if the connection is there and my sight is failing me, telemetry to the rescue :-).
But if connection is broken and in ATTI? This is when you start to pray :-)
However, this tip comes very handy when your DJI GO app crashes or your mobile runs out of battery and you can only rely on your eyes and RC with no display.  

Many thanks S-e-ven!

S-e-ven Posted at 2018-6-14 11:34
Just one more thing:
If I have no video stream, (my app is chrashing every now and then ;-), I like it better to fly home backwards !
Controls and bird moving 1:1 and not opposite directions.

True, i always land backwards it the landing spot is kind of tricky.

Hi. Thank you for raising your concern to us. If the GPS connection is lost the Spark's RTHF will automatically work so that you will be able to recover the drone and it will not fly away.

Mirek6 Posted at 2018-6-14 11:39
You know, this right/left tip is really good. I did not think about it since if the connection is there and my sight is failing me, telemetry to the rescue :-).
But if connection is broken and in ATTI? This is when you start to pray :-)
However, this tip comes very handy when your DJI GO app crashes or your mobile runs out of battery and you can only rely on your eyes and RC with no display.  

I was Praying today , i lost connection 1.4 km from take off point .. had black screen for at least 25 seconds... then all of a sudden  it cam back on with return to home beeping and video  back on, at that point sparky was only 500 meters away

PHEW is all i could say as i did not really  have a clue where it was .

Mirek6 Posted at 2018-6-14 11:14
A CW,

Very good advise. I would add that it is advisable to invest in antenna range boosters for wifi drones like Spark. They cost 15 bucks and are worth additional piece of mind. Spark is tiny, and even with VLOS and within short distance, it is easy to loose sight of it. If it enters ATTI and you cannot see it (even if it is within line of sight) and, on top of it you lose signal between AC and RC - you are in trouble.

Thanks      

Harry Moman Posted at 2018-6-26 00:59
I was Praying today , i lost connection 1.4 km from take off point .. had black screen for at least 25 seconds... then all of a sudden  it cam back on with return to home beeping and video  back on, at that point sparky was only 500 meters away

PHEW is all i could say as i did not really  have a clue where it was .

Good post! Trust your Spark - it is worthy of your trust.

But, while trusting, avoid doing anything silly :-)

I did many experiments of fail safe returns - work like a charm. But if I want to test fail safe or push the distance boundary, I would choose very, very calm day. If it it is windy and wind sheer and gusts confuse your Spark to experience yaw errors and drop to ATTI, and than you lose signal? ... Hmmm... but power of prayer should not be underestimated :-)

Thanks for encouraging post.

Mirek

Mirek6 Posted at 2018-6-26 05:56
Good post! Trust your Spark - it is worthy of your trust.

But, while trusting, avoid doing anything silly :-)

Through your experiments did you ever discover what the drone does if you lose GPS, enter ATTI mode then lose signal? I guess you'll just lose the drone?

A CW Posted at 2018-6-26 06:58
Through your experiments did you ever discover what the drone does if you lose GPS, enter ATTI mode then lose signal? I guess you'll just lose the drone?

A CW,

I just replied to similar question on other thread:

When Spark loses signal in ATTI mode it is programmed to land. It knows that it is in ATTI, it knows that pilot is out of range and it cannot do anything to control it manually so the only logical option is to land (instead of being pushed to God-knows-where until battery dies and landing is forced).

So Spark will start to land. But it will not fully land. Short distance above the ground it will stop, hover and wait for one of three things:
1. Return of GPS communication (than it can fly back home in fail safe mode).
2. Restoration of communication with the RC so the pilot can tell it what to do.
3. Battery getting to critical level, at which time the Spark will finish landing.

The additional fly in the ointment here is that if Spark finishes his ATTI landing sequence over water, it may not wait for conditions 2 or 3 above, but instead could take a happy and refreshing swim with VPS fooled by reflections on the water suggesting to it that it is still high and can continue landing.

So, i you find yourself in position 3, check the trajectory along which wind was pushing your drone and check the drone altitude and speed with which it was moving pushed by the wind.  Calculate where the drone was 3 seconds after it lost the signal (this is when it will start to land). Calculate how much time the drone needs to land (it lands with speeds 1-3 m/s). Calculate its landing trajectory and look for it there.

That makes sense - thanks so much for clarifying

Mirek6 Posted at 2018-6-26 07:22
A CW,

I just replied to similar question on other thread:

Hi Mirek,

Interesting case about autolanding in ATTI when loose connection.
Did you test this out or read it somewhere?

So if i fly in ATTI (let`s say free open space) and i cannot control it...switching of my RC will make in autoland?  That`s mayby better than let it drift away and finally at long distance go into autoland.

Or do i make i mistake now?

[ test: let me think, put kitchen alu foil on top Spark, get into the air in ATTI and switch off RC? ]

cheers
JJB

JJBspark Posted at 2018-6-26 10:00
Hi Mirek,

Interesting case about autolanding in ATTI when loose connection.

JJB,

No, I did not test it myself but I have read several posts on this forum where more experienced forum members claim this to be true. However, being inquisitive me, I follow old Russian proverb (no, I am not Russian :-) -  Dovyeryai no provyeryai - Trust but Verify.

So I verified and found some videos on youtube (even some posted on this forum with logs) where I saw with my very eyes the following sequence:
- Spark flies happily.
- Spark drops to Atti for whatever reason.
- Spark start drifting away (video confirms)
- Spark loses connection (video shows continuous drift but Spark is lowering altitude)
- Spark gets close to the ground and hovers there without landing
- Suddenly Spark goes into P-GPS mode (perhaps compass and IMU rested a bit while hovering motionlessly above the ground :-).
- Spark perks up and returns home.

Happy owner posts video of the entire journey.

So I have seen some evidence and heard from more experienced than me. Also, I think it would be silly if DJI designers did not do it this way.

But... there are two flies in my ointment:
1. I have seen DJI Elektra proclaiming that Spark would just hover. I don't believe she understood the question though.
2. I did not try it myself.

If you try your experiment and prove me wrong, I will be devastated. Not because you proved me wrong, but because of my brain being twisted in knots how to reconcile what I have said and seen with what you reported :-).

Please share with us your results. You would be the first one who knows what he was doing and did it conscieously.

DJI Stephen Posted at 2018-6-16 06:47
Hi. Thank you for raising your concern to us. If the GPS connection is lost the Spark's RTHF will automatically work so that you will be able to recover the drone and it will not fly away.

What is RTHF? If "return to home function", how does that work without GPS?

stuka75 Posted at 2018-6-27 05:09
What is RTHF? If "return to home function", how does that work without GPS?

Something must have been lost in translation :-).
If GPS connection gets lost RTH is useless (until the moment GPS is on again).
I think DJI Stephen meant RC to Spark Wifi connection - not GPS connection.

DMX_MT Posted at 2018-6-14 10:04
Everyone has the right to express his own opinion.

I just told JJB that the subject is on GPS Loss not on a Preflight checklist, if you can read, you can understand.

you're a clown