So after a bit of debugging, I've figured out what the issue is with the Spark and the Pixel XL, and I have a workaround.

A brief history of wifi

On 2.4GHz, the channels supported everywhere run from 1 to 11. In various locations 12, 13, and 14 are permissible. This is very simple and well-supported.

On 5GHz, where channels run from 36 to 165, things get more complicated. Not only do various countries have their own individual power limits and channel list, but the over-the-horizon radar capabilities of each nation often clash with the frequencies inside the band. Instead of blocking those frequencies completely, an interesting compromise was reached - DFS, or Dynamic Frequency Selection. With DFS, devices broadcasting a network regularly stop and listen for radar activity. If they find it, they take a variety of actions, including switching frequency, dropping transmit power, or if they can't do anything else, shutting the radio off completely for a period of time. DFS is a good thing - since radar activity isn't common, it's a decent compromise that gives us way more spectrum to play with than we would otherwise have.

The trouble is, when DFS activates, it can be incredibly difficult to understand why. Users just see their network dropping out. For this reason, some manufacturers choose to just avoid DFS support entirely, and block access to DFS channels.

Now, back to the Spark. When it starts up, unless configured otherwise, it tries to find somewhere quiet on the 2.4GHz band. If it finds one, great - no problem. If it doesn't, which is quite common in built-up areas, it switches to 5GHz and things start to go sideways.

The trouble is that the Spark will happily use both DFS channels, and channels used outside your region. This is a questionable design decision, but it's what we've got. The end result is that it finds itself somewhere quiet around channel 149, and broadcasts away.

The Pixel XL does not support DFS channels and it enforces region restrictions. As a result, the Pixel XL will not even scan on channel 149. The Spark thinks it's done the right thing and everything's fine, and the Pixel XL can't see it because it's outside its working band.

What DJI need to do


I would like to see DJI allow us to lock it to 2.4GHz, even if the band is noisy. That way at least we can connect to the quad. If DJI want to warn about strong interference on wifi at that point, that would make sense.

What you can do in the meantime


Until that happens, the workaround is fairly simple - reset the wifi each time you power the quad on. Power up, give it a few seconds to finish startup, then hold the power button for 9 seconds - you'll hear one, then two, then three beeps. Release the power button, and the quad will reset its wifi and force itself to the best 2.4GHz channel it can find, at which point the front LEDs will light up green. You'll then be able to connect.

You will have to do this every time you power the quad up, and of course custom SSIDs and keys will be unusable. You're also not getting around the root issue, that the wifi control channel is very noisy (using the hardware remote controller might be a way around that, but I don't have one to test with), so be very, very careful when you're flying, and make sure your RTH settings are correct. If the quad loses wifi connectivity for 20 seconds it'll automatically RTH, and the odds of that happening with a noisy wifi band are high.

good analysis of the problem.  DJI should really improve the firmware of the spark so you can disable automaticly switching to the 5.8 hz band. Especially for Europe this should be disabled by default.

Another workaround (besides resetting the spark everytime) is rooting your android device and setting the wifi region to China or US.  Then the wifi of the spark on the 5.8 band is also recognized.

Thanks for this information. I found it really helpful.

Thanks for the insight. Question, how can you tell if a device/smartphone supports DFS?
For instance, I experience this issue on Xiaomi Mi3 but not with Lenovo 7000 Plus I can always connect to Spark seamlessly using it. In gsmarena, I found that Pixel XL has almost the same wifi specs with Xiaomi Mi 3
Mi3: Wi-Fi 802.11 a/b/g/n, dual-band, Wi-Fi Direct, hotspot
Pixel XL: Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, DLNA, hotspot
while Lenovo A7000 Plus has Wi-Fi 802.11 b/g/n, hotspot only.

Now i see..! This has to go to DJI support! This looks like the base of the problem. Every thing make sens. But how to make our smartphone see the DFS without the need of root.

Szwedu Posted at 2017-6-22 00:46
Now i see..! This has to go to DJI support! This looks like the base of the problem. Every thing make sens. But how to make our smartphone see the DFS without the need of root.

sorry, you can't. In Android stock the wifi region is set by the simcard region.

Only way to change this is to root and use a custom rom like lineage OS to set the wifi region or use app like Wifi codes https://forum.xda-developers.com/showthread.php?t=1982149

So we are waiting for the update... Its so wired that sach a big company did implement WiFi ac bands that are not available in Europe...

fans9888dba9 Posted at 2017-6-22 12:09
sorry, you can't. In Android stock the wifi region is set by the simcard region.

Only way to change this is to root and use a custom rom like lineage OS to set the wifi region or use app like Wifi codes https://forum.xda-developers.com/showthread.php?t=1982149

OP has uploaded to a site that forces adware on pc to download, does anyone have a mirror please.
https://forum.xda-developers.com ... 34&postcount=61

I see this possibility that i use Palm lunch for a quick selfie , wave at it to go 3m up and than for some reason it cant read my gestures . At that point i cant connect to it because i cant reach it to reset the wifi. So it will sit there till the battery runs out and land or crash ? I am curies if someone had an issue that the drone didn't react to Bacon .

Szwedu Posted at 2017-6-23 03:11
I see this possibility that i use Palm lunch for a quick selfie , wave at it to go 3m up and than for some reason it cant read my gestures . At that point i cant connect to it because i cant reach it to reset the wifi. So it will sit there till the battery runs out and land or crash ? I am curies if someone had an issue that the drone didn't react to Bacon .

I did. As per DJI's video tutorial, I connected to Spark's wifi first before I do the gesture mode when it didn't recognized my gesture (probably because it's a bit dark that time only a street light as the source) I picked up my phone to manually control it but unfortunately it hangs and there's a beeping sound in DJI Go app, I noticed that it lost connection to the Spark because my phone switches to my home's wifi network. A lesson for me is to disable auto-connect to other saved wifi network.
I tried the gesture mode in the dusk, works as expected.

I have the same issue ongoing with connecting via my MotoX.
Thanks for the explanation. Well done!

Let's hope DJI will wake up and fix that with an according patch.

Just got my Spark, and it's asking for the password when I am connecting to the wifi "Spark-XXX", anyone knows what password should I use?
Thanks

You got it on the drone battery compartment and on the foam box.

ilanos Posted at 2017-6-23 11:00
Just got my Spark, and it's asking for the password when I am connecting to the wifi "Spark-XXX", anyone knows what password should I use?
Thanks

I suggest you try this:
https://dl.djicdn.com/downloads/ ... ser+Manual+V1.2.pdf

Same problem here with a Samsung Galaxy S5. For now I'm always doing the 3-beep-trick to reset the Wifi

There are a few information I would like to make it clear.
1. On 2.4Ghz, the channels do support everywhere run from 1 to 11, a portion of countries support 1-13 channels, but 14 channel is barely permissible in most countries.
2. 5Ghz frequency include three bands, Spark only support 149-165 channel. Usually channel 36 to channel 48 are used indoors (Spark is recommended to fly outdoors); Channel 52 to channel 140 belong to DFS which will need 1 minute channel availability check time. The most important thing is that indoor channel is not allowed to be used outdoor, with DFS, it would take more than 1 minute to access wifi hotspot.
3. For the better customer experience, if you activate Spark with the mobile device that support 5.8Ghz, Spark will record the data, otherwise, the frequency will be locked on 2.4Ghz all the time.

That's not the problem , because after turning on the spark there is no ssid on the 2.4 band and on 5.8 , checked on different devices.

Hm. I did also some further testing and it seems to be an Android issue?! So for my Samsung Galaxy S5 the SSID of Spark does not appear, same for an Huawei Honor 7, but my Ubuntu Laptop, iPhone 5 and iPad Air 2 were able to find the SSID of the Spark.

Side note: The iPhone 5 took about 25 seconds to see the Sparks SSID (other networks were found within ~3 seconds)

I don't have iOS, can't test that. Today I again tryed to connect to 5ghz , went to open field, reset everything in airplane mode but no luck, my OnePlus one can't see it.

Same to me. Spark is locked on channel 149 but in EU we don't have channel 149 on 5GHz. Any info when the issue will be fix ?

DJI Mindy Posted at 2017-6-28 00:21
There are a few information I would like to make it clear.
1. On 2.4Ghz, the channels do support everywhere run from 1 to 11, a portion of countries support 1-13 channels, but 14 channel is barely permissible in most countries.
2. 5Ghz frequency include three bands, Spark only support 149-165 channel. Usually channel 36 to channel 48 are used indoors (Spark is recommended to fly outdoors); Channel 52 to channel 140 belong to DFS which will need 1 minute channel availability check time. The most important thing is that indoor channel is not allowed to be used outdoor, with DFS, it would take more than 1 minute to access wifi hotspot.

@DJI Mindy - unfortunately Android devices rarely (if ever) support 149-165 in at least the EU region. If the only 5GHz channels supported by Spark are 149-165 (and I understand your reasoning, it's acceptable) then we need a way to force Spark to only assign itself to 2.4GHz regardless of what it thinks the device is capable of. The Pixel, for example, would report itself as 5GHz capable - but that doesn't change the fact that it can't use channels 149-165.

DJI you didn't know that  WTF?


This is insane , so you know you have to cut down the strenght of the signal in europe by the rules of FCC and CE but that simple thing like usable channels in difrent region got some how missed ?

Szwedu Posted at 2017-6-28 11:58
I don't have iOS, can't test that. Today I again tryed to connect to 5ghz , went to open field, reset everything in airplane mode but no luck, my OnePlus one can't see it.

Can see the drone on 5Ghz wifi on every boot with this simple trick ;)

fansb77449ae Posted at 2017-6-29 06:19
Can see the drone on 5Ghz wifi on every boot with this simple trick ;)[view_image]

I assume you're using WiFix? I appreciate you're happy about it and don't have any malicious intent, but it muddies the waters a bit when we're trying to convince DJI that this is a real issue. The tool you're using -

* requires root and/or a custom Android ROM
* is only available from shady, malware-ridden download sites
* doesn't work on every device

As a result, it really isn't a feasible workaround for the majority of users.

Szwedu Posted at 2017-6-29 03:24
DJI you didn't know that  WTF?

@Szwedu can you link me to where you found that table? I've been looking for that exact data presented in a readable way, and that is perfect.

daveio Posted at 2017-6-29 08:18
@Szwedu can you link me to where you found that table? I've been looking for that exact data presented in a readable way, and that is perfect.

It's in Polish hope you can use google translate and make some of it.
http://winet.com.pl/Sieci_WLAN_rozk_ad_kana_w_pasmo_5GHz.htm

daveio Posted at 2017-6-29 08:16
I assume you're using WiFix? I appreciate you're happy about it and don't have any malicious intent, but it muddies the waters a bit when we're trying to convince DJI that this is a real issue. The tool you're using -

* requires root and/or a custom Android ROM

Acually im not using that app, it doesn't work for me. My rom has it baked in already.

There is also a nice one from Parrot, we went through this  waaayyy before DJI ;-)

Nils

http://blog.parrot.com/2014/11/2 ... -flight-range-test/
(Scroll down for regulations)

Szwedu Posted at 2017-6-29 13:03
It's in Polish hope you can use google translate and make some of it.
http://winet.com.pl/Sieci_WLAN_rozk_ad_kana_w_pasmo_5GHz.htm

@Szwedu translation is no problem. Thanks so much, that's perfect. All the centre frequencies nicely listed, that's going on my wall. Thankyou!

I have same problem with Samsung Galaxy S7 in Czech Republic... My phone don't see Spark SSID after Spark restart... Only chance for see SSID is reset WiFi in Spark (9s holding battery button)

I'm also having the same problem on Nexus 5x in the UK.

Assuming DJI fixed this issue via FW update, is there any advantage in using 5GHz in EU? It looks like we will get significantly reduced transmission distance using 5GHz. See image below from the manual.

Even using 2.4Ghz I get low signal warnings when the Spark is only 30m away from me. Little disapointed in this. Has anyone been able to fly further using a different type of phone? Is Iphone better?  

fansb2281168 Posted at 2017-7-1 15:18
I'm also having the same problem on Nexus 5x in the UK.

Assuming DJI fixed this issue via FW update, is there any advantage in using 5GHz in EU? It looks like we will get significantly reduced transmission distance using 5GHz. See image below from the manual.

@fansb2281168 30m using smartphone-only control seems about right. I believe the figures you're talking about refer to flight using the hardware remote controller.

I'm having the same problem. Having to reset the WiFi settings using the 9 second button press. Disappointed. I've got 2 devices S7 Edge(2.4+5GHz) and an old Hudll (2.4GHz).Getting the same thing on both. For its initial connection everything worked fine but then it said "switching WiFi you your country" and that's when it misbehaves.

After resetting the WiFi it connects on 2.4GHz. Dji needs a solution that remembers that for next time to save that so resetting is not required.

Resetting the WiFi looses SSID and password changes... annoying.

Summary 2 annoying issues that are easy fixes in firmware.  It's tarnished my view of the drone and as my first use of DJI products doesn't leave a good impression.

I'm having the same problem. Having to reset the WiFi settings using the 9 second button press. Disappointed. I've got 2 devices S7 Edge(2.4+5GHz) and an old Hudll (2.4GHz).Getting the same thing on both. For its initial connection everything worked fine but then it said "switching WiFi you your country" and that's when it misbehaves.

After resetting the WiFi it connects on 2.4GHz. Dji needs a solution that remembers that for next time to save that so resetting is not required.

Resetting the WiFi looses SSID and password changes... annoying.

Summary 2 annoying issues that are easy fixes in firmware.  It's tarnished my view of the drone and as my first use of DJI products doesn't leave a good impression.

Same here in the Netherlands,  Samsung S7 Edge,  Latest update/Euro version.
(It does work fine with an US IPad here.)

Let's summarise:
On 5Ghz band, 149 channel configured by spark after initial setup is not available in eu. So this is a BIG BUG. Do we have any official position from DJI?

fansb6af2642 Posted at 2017-7-2 04:55
Let's summarise:
On 5Ghz band, 149 channel configured by spark after initial setup is not available in eu. So this is a BIG BUG. Do we have any official position from DJI?

No. Nothing further from DJI since @DJI Mindy's replies above. Until a fix rolls out, you'll need to use the workaround of the 9-second reset each time.

Same problem in Spain, with Moto Nexus 6

Same problem. Ireland.  Come on DJI. Update Update!

If we read the specifications sheet on DJI page will see:
Operating Frequency        2.400 - 2.483 GHz; 5.725 - 5.825 GHz. This means Spark is not dual band in Europe because of hardware or this can be modified? I realy couries if its hardware limitation , apart from that the 5ghz in europe is useless becaus of signal strenght ...