Using Spark with RC.

What is the minimum Galaxy S series phone, that will work without any video lag?

Obviously OTG support is needed.

Must be Android based.

Yes, there are lists of what is recommended. But that wont answer the minimum nor zero image lag.

Having minimum or zero lag is quite subjective. I use a sub $150 Android device called Moto E4 Plus with OTG and if you ask me, I get zero lag.

So I'm a little confused about lag.  If I'm taking a photo of a car crossing over a small bridge, do I take the picture when I see on my mobile device the car on the bridge...or do I take the picture when I visually see the car with my own eyes on the bridge???

The drone captures images realtime on its SD card, so that's the one you want rather than the (delayed) image on the phone. Usually the RC - Phone image delay will be around 300 ms, OTG helps to decrease that slightly.  Disabling video caching also supposedly helps lower end devices keeping up.

Galaxy S5 since day one/2017 here, it was a spare phone i had left from upgrading, and it has never lagged.

Tried an S4 but that was pushing it.

I also use otg, witch it works perfect with, but i am also using 4.1.15, and have never looked back or had any issues with it.

warubikku Posted at 3-3 23:40
Galaxy S5 since day one/2017 here, it was a spare phone i had left from upgrading, and it has never lagged.

Tried an S4 but that was pushing it.

I downgraded to 4.1.15 with a Galaxy S4.  The lag was terrible -- the same as with 4.3.14
The "Lag" I'm talking about is the time it takes from what the drone camera sees, to when you see that on the cell phone screen.
I set a stop watch. hold the drone in my hand (not flying), turn the drone to a different dirrection... it takes about 5 seconds for the image on the phone to change. OTG will not work with the S4, I tried everything I could to reasonably strip down the S4 to reduce this. Finally looking at buying another phone for Mr. Spark. However I'm a cheap SOB, so I'm looking at what will do it best, yet reduce the cost outlay. As I'm new to Drone world, I may upgrade / expand and get other AC's in the future. Then I might purchase more elaborate equipment to accompany..

djiuser_NCXRokNslVsT Posted at 3-5 05:53
I downgraded to 4.1.15 with a Galaxy S4.  The lag was terrible -- the same as with 4.3.14
The "Lag" I'm talking about is the time it takes from what the drone camera sees, to when you see that on the cell phone screen.
I set a stop watch. hold the drone in my hand (not flying), turn the drone to a different dirrection... it takes about 5 seconds for the image on the phone to change. OTG will not work with the S4, I tried everything I could to reasonably strip down the S4 to reduce this. Finally looking at buying another phone for Mr. Spark. However I'm a cheap SOB, so I'm looking at what will do it best, yet reduce the cost outlay. As I'm new to Drone world, I may upgrade / expand and get other AC's in the future. Then I might purchase more elaborate equipment to accompany..

5 sec is not normal at all!
As answered by others, 0.3 sec is.

Safe flights

Haggi Posted at 3-5 06:05
5 sec is not normal at all!
As answered by others, 0.3 sec is.

That is what I thought.   0.3 second would be fine, for my use.  So I'm looking for solutions. As nothing seems to work with the Galaxy S4 than I'm looking for an inexpensive replacement. However tht replacement should have some other uses. So as to negate some of the costs of acquisition.

Rustic17 Posted at 3-3 22:44
So I'm a little confused about lag.  If I'm taking a photo of a car crossing over a small bridge, do I take the picture when I see on my mobile device the car on the bridge...or do I take the picture when I visually see the car with my own eyes on the bridge???

The lag is in milli-seconds. The car cannot cross the bridge in such a short time frame. And if your are at a good distance away, you can easily take 2 or 3 shots till the car crosses your frame and keep the best one.

nilanjan118 Posted at 3-5 18:40
The lag is in milli-seconds. The car cannot cross the bridge in such a short time frame. And if your are at a good distance away, you can easily take 2 or 3 shots till the car crosses your frame and keep the best one.

My lag is not in miliseconds. My lag is in full seconds. Five of them closer to six. So 5 seconds lag is enough to miss everything. Including that tree, house, vehicle, wire or any other obstruction.

djiuser_NCXRokNslVsT Posted at 3-5 18:46
My lag is not in miliseconds. My lag is in full seconds. Five of them closer to six. So 5 seconds lag is enough to miss everything. Including that tree, house, vehicle, wire or any other obstruction.

Well that's not normal. I was talking from my own experience about the "lag" I get. I use an Android device with OTG cable.

nilanjan118 Posted at 3-5 18:50
Well that's not normal. I was talking from my own experience about the "lag" I get. I use an Android device with OTG cable.

Now you can see why I'm trying so hard to find a solution.
This is the lag, without even flying. Just sitting on the ground.
I believe with the OTG cable it would be a huge difference but no one has yet come up with a realistic way of getting the S4 to recognize the OTG and go into Host mode. I'm not willing to root this phone but even that might not achive USB Host mide.

djiuser_NCXRokNslVsT Posted at 3-5 18:56
Now you can see why I'm trying so hard to find a solution.
This is the lag, without even flying. Just sitting on the ground.
I believe with the OTG cable it would be a huge difference but no one has yet come up with a realistic way of getting the S4 to recognize the OTG and go into Host mode. I'm not willing to root this phone but even that might not achive USB Host mide.

I understand. I am no expert to solve your problem but I can only say that I would never take-off if I had even 1 sec lag. Something is wrong with either your drone or your phone. I hope you find a solution soon. Good luck.

I'm using a Galaxy S4 mini VE. With Wifi connection to R/C, that is not usable, several seconds lag time. With OTG cable, no problem, no noticable video lag since then.
Tried with a stock 4.2.20 app (did work nicely with OTG), but now using MOD 2.0 app for FCC reasons.

Cheers,
Wolferl

Wolferl Posted at 3-6 04:02
I'm using a Galaxy S4 mini VE. With Wifi connection to R/C, that is not usable, several seconds lag time. With OTG cable, no problem, no noticable video lag since then.
Tried with a stock 4.2.20 app (did work nicely with OTG), but now using MOD 2.0 app for FCC reasons.

Wolfer,  First I've heard of the Galaxy S4 Mini but not sure what the "Ve", variant would be. If I understand you, correctly, you are able to use the OTG cable with your Galaxy S4 Mini?  But you were not able to use it well with just WiFi? Am I understanding correctly?
I am not a guru on cell phones. Isn't the S4 Mini a lesser capable version of the regular S4? My S4 is on the Verizon network. Does that mean anything as far as built in limitations?
I have spoken with Verizon and Samsung, they say it is not possible to have my S4 go into USB Host mode (the reason to use OTG). the S4 will not recognize / offer that option.
The delay I write of is not a delay between commands and results from RC to AC. The commands seem to happen instantly. The delay is just the image / video feed seen on the S4. If I move the joystick on the RC the AC turns immediately, however the screen on the S4 shows the image, seen by the AC camera moving about 5 seconds later. So the problem is when flying I am reacting to things 5 seconds too late, if going by the S4 screen. Of course I don't know about the telemetry as I have not tested that.
So are you saying that with just WiFi, this setup should not have a 5 second delay?
I have the S4 stripped down to approx. 4.5GB available onboard RAM. Airplane mode, Killed most other apps, no SIM, 64GBexternal SD, Tried to turn off Cache but still have not conquered it.
All the equipment is new (now a couple of months old), except the S4.
The OTG was purchased from DJI or B&H (I don't remember now), so they are DJI brand.
Ideas????????

RC end of cable should be the Host end, not Phone end of cable.
OTG cables are directional (one way).
If you have an OTG cable with micro-usb in both ends, turn it around if it doesnt work.
When success, remember to mark the cable...so you remember next time :-)

To explain why it's directional:
An OTG cable is really just a modified usb cable.. one cord is cut, and in the host end the other end of same cord is soldered to another cord.
If used the wrong way, most likely the RC will charge your device.
On most devices there is no need to enter Developers Options to activate anything...

Haggi Posted at 3-6 07:36
To explain why it's directional:
An OTG cable is really just a modified usb cable.. one cord is cut, and in the host end the other end of same cord is soldered to another cord.
If used the wrong way, most likely the RC will charge your device.

My OTG cable is Micro USB Male B on one end and USB Female A on the other end.
Using this with the DJI supplied USB A Male to Micro USB Male cable.
Therefore the two USB A ends are always joined.
With OTG Micro plugged into RC and regular USB Micro plugged into S4, phone starts charging, therefore, based upon what you state, this is the wrong direction. However, interestingly, the Go4 app starts up.

With OTG into S4 and regular USB Micro into RC, no charge detected. Which, based upon what you wrote, should mean it is correct orientation.
Then I start the Go4 app.
However when Go4 is running, no video signal / communication with controller.
Only way to communicate with RC is via WiFi.
Attached are three screenshots, with WiFi NOT set to RC link.
Image 1 "S4 OTG no WiFi" shows Go4 app with the above configuration: Where display says RC Connected (bottom left) yet RC is not communicating with S4.
Image 2 "S4 OTG USB Options"  is choices available when USB cable is connected to S4. MTP or PTP. No option for USB Host.
I do not, currently have a phone that will tell me what the other USB option should look like.
I have tried MTP & PTP & selecting nothing. No communication.
I have tested the OTG cable for other functions.

I have another Galaxy S5 (not S4), here. I have set it into Developer mode and enabled USB debugging.  Although I cannot put the Go4 software into the S5. But I did run a brief test of the OTG options. Interestingly, with OTG plugged into S5 (wrong way?) then S5 starts to charge, however it allows for USB mode selections...See screenshot Image 3 "S5 OTG USB options".  I believe I would have to select MIDI for communication with RC.
Reversing cable on the S5 does not charge nor allow these USB mode options.

On the S4 I have also tested the OTG cable for other communication. It allows me to use a mouse, access thumb drives etc. So I believe the OTG cable is functional.

Am I missing something? Is there a setting in Go 4 app,  that enables cable connection to the RC?

Sorry for such a long winded posting.

Forget the S5 since you will not run GO 4 on that..

I do not know your S4's android version, but alot of people on older versions claim you need to enable usb debugging in "Developer Options".
Maybe its worth a try.
After this you should be able to connect.. with the correct cable.. where otg end is in RC.

My OTG procedure (Android):

• Turn on Remote Control (RC). Wait for solid red.
• Plug in OTG cable in phone.
• Plug other end in RC.
• Choose DJI GO 4 app in popup window.
• Wait until GO 4 app is open and it says "RC Connected" in lower left corner.
• Power up your Spark. Try to place RC as close to Spark as possible. (DJI recommend 20 cm)
• Bonding between RC and Spark should take less than 30 sec.
• Hit GO FLY!
  

The S5 info was just so you would see the difference in the USB mode options. I beleive that is why the OTG cable will not work.
I have 2) Galaxy S4 cell phones. Both are running Android 5.0.1,  Developer options on, USB debugging on.
Have tried GO4 versions 4.1.15,  4.3.4,  4.3.14 (current version).
I have done the hook up exactly as you stated.
Same problem.

As to you mentioning "RC Connected" in lower left corner., that displays in the GO4 app even when the RC is not connected. The S4 WiFi was not set to the RC. I could not get an image to display from the AC even though the AC & RC were linked to each other (green light on controller). It showed as connected even though no image transfer. As soon as I turned WiFi to the RC channel...the image from the AC came on the S4.
The AC is getting it's communication from the RC. In test flights I have flown way beyond the limits of the S4 WiFi range. I beleive it is jsut the communication between S4 & RC is only going through WiFi. That is why I want to use OTG.

Have you ever tried OTG with an S4?

OTG with an S4? No
But I've done OTG with even older S2!

Check out these settings:


I have no other suggestions, you have to search the net.
Or another guy with S4 need to surface..

djiuser_NCXRokNslVsT Posted at 3-6 06:51
Wolfer,  First I've heard of the Galaxy S4 Mini but not sure what the "Ve", variant would be. If I understand you, correctly, you are able to use the OTG cable with your Galaxy S4 Mini?  But you were not able to use it well with just WiFi? Am I understanding correctly?
I am not a guru on cell phones. Isn't the S4 Mini a lesser capable version of the regular S4? My S4 is on the Verizon network. Does that mean anything as far as built in limitations?
I have spoken with Verizon and Samsung, they say it is not possible to have my S4 go into USB Host mode (the reason to use OTG). the S4 will not recognize / offer that option.

Hi,

The "VE" stands for value edition, and is a later version of the standard S4 mini. The standard one is called GT-I9195, the VE is GT-I9195i. It has slightly enhanced performance, but looks exact the same the the standard model.

Yes, I am using it with an OTG cable from Amazon. The host end of that cable goes into the R/C, so it is not needed for the phone to act as a host.
The S4 mini is just an S4 with a smaller display and less memory.
Indeed, if I just use Wifi, not the OTG cable, there is very long lag in the video feed.
I am using that phone with Android 7.1 "lineageOS".

Cheers,
Wolferl

Thanks Wlferl, I'm on the lookout for another phone to use. I'm just a  bit stubburn  that, I'm going to feel like a fool if I get another phone and either...
A) Still have the same problem
B) Then find out I could have resolved this with the S4 I already had.

Try a friend's S6-S9 whatever..
Download GO 4 app.. Log in the app with your credentials.
Try startup with OTG cable, it should work right out of the box, since your drone is registered and connection between AC and RC is established.
You can do this in house, its only a cable test :-)
When finished and happy, just delete app on friends phone. No harm done.
If you have no success, then your cable or the way you connect it, is def wrong.

Edit: Be aware you need a otg adapter in RC end anyway

Video transmission between the AC and RC is digital so forget about 0 lag. Even before it reaches the phone, lag is around 170ms. I guess 200ms is ok if you don't go too fast.
And that's why fast racing drones use analog transmission, it's usually at least triple as fast as digital (in 50, 60ms lag range).

Ahhh but in a perfect world I would experience 0 lag  :-)
Ok, 200ms I would not complain about. However I am getting 25 times worse than that. I'm at 5000ms to 6000ms
At top speed I believe Spark would go about 250 feet before I would see tthe change on my display.
So zipping through and finding that tree branch... UGH!
Yes, thanks for obstacle avoidance etc. But I need a close to real time display.
Seeing that whale leap and getting the shot...oopes what I just saw happened 5 seconds ago...too bad.

BTW I changed my handle from "djiuser_NCXRokNslVsT" to the current one.

New test.
I just installed the GO 4   4.3.14 app on a Galaxy S5 cell phone.
This S5 has lots of other apps on it. Has lots of storage being occupied.
I never turned WiFi on.
used the OTG cable on RC side, selected MiDi. (BTW it insisted on trying to charge the cell phone).
Flew the Spark.
No noticable lag, at all.
Very quick video feed from Spak too S5.
Even with the Cache on & recording of video on.
No lag !!!!!!
So conclusion... OTG cable - good:  Spark - good:  RC - Good:   S4 with OTG - BAD.
Looking for another phone.

Congrats, mate!!
Great news :-)
I still think MTP is the correct protocol, midi sounds like something from the -90's.
But, hey... whatever works for you, pilot!

Thanks :-)
I feel like I'm a glider pilot. Still tethered to the AC towing me along  :-)
However I did have the enjoyment of scaring the cats, while flying it indoors, for the test.

Haggi Posted at 3-7 15:20
Congrats, mate!!
Great news :-)
I still think MTP is the correct protocol, midi sounds like something from the -90's.

MTP is available on the S4. It wont work with the OTG cable. On the S5 I selected MIDI and it work fine.
I agree with you on MIDI seeming like what was used for music, back in the day.
Perhaps it has nothing to do with the choice on the phone and just the ability of it to inernaly recognize the USB host setting?
Either way, it worked so I'm going forward with trying to obtain another phone.

GetHigh Posted at 3-7 21:40
MTP is available on the S4. It wont work with the OTG cable. On the S5 I selected MIDI and it work fine.
I agree with you on MIDI seeming like what was used for music, back in the day.
Perhaps it has nothing to do with the choice on the phone and just the ability of it to inernaly recognize the USB host setting?

Great you got it to work properly. It's sooo much nicer to fly with a low-lag video feed, isn't it?

Cheers,
Wolferl

GetHigh Posted at 3-7 14:56
New test.
I just installed the GO 4   4.3.14 app on a Galaxy S5 cell phone.
This S5 has lots of other apps on it. Has lots of storage being occupied.

Ok, challenge accepted. Got really really crappy and cheap Samsung Galaxy E5 with Android 4.4.4 and DJI Go 4.1.15 and yes, OTG.... lag in 200ms range. Good thing is it has an AMOLED screen so somewhat better readable in a daylight.