Who can use 640x480 30FPS in DJI App.. possible fix

[justin00]

Well stay tuned Frank
And thanks for info Burlbark.

I am just finalizing my 'oh-my-god-I-typed-in-something-wrong-and-bricked-wifi-mobile" failsafe script and then I shall release details, script and the howto.

Basically the idea of the script is is to create backup of the wireless config, make your changes, once you reboot if the wifi module access point software "HostapD" does not come back up within 10 mins or detects criticals errors after it auto revert back to back up config and reboots and presto... wifi back in action. no bricked wifi.

Also playing a around with a few more settings to see if can get an extra few hundred feet out of it.... At the moment can goto 1000ft without any drops.... have not tested any longer as I do not have a big area to test in (very residential)

Way over kill for for basic linux users, but that doesn't cover a large portion of the folks here I suspect so want to make it foolproof.. which is why never released any other linuxy backend stuff before...

Will go out for a final flight tonight and then peoples can test her out and hopefully get 640x480 good ness.

 

[flyNfrank]

Well I'm getting close to the end of my night here as it's a little after 2:00am now. I'm still quadless so I'll just be a viewing and not a tester.

 

[Str8rippin]

I use 640x480 30fps can get to around 400m with it no dramas, it's definatly your phone, go get an iPhone 6 and try

 

[bbfpv]

640x480/30 here as well, on a Droid Turbo. But I'm using FPV Booster and have from the very beginning on both my p2v+. Both are v3 w/ the new wifi modules.

 

[flyNfrank]

Where is the info at? I thought this would have been on here yesterday based on what you said. Although, no hurry....

 

[robinb]

I use 640x480 30fps can get to around 400m with it no dramas, it's definatly your phone, go get an iPhone 6 and try

Same here I was getting 420 meters yesterday without any boosting of signal.

I was going to try the booster but it was cold and I had enough for day.

I use a galaxy tab S 8.4

 

[justin00]

Sent ya a PM...

*edit* deleted orig message. Going to post up this weekend.. Just busy with valentines day weekend and work stuff and am worried someone going to brick wifi module.. I need to stop being a *****.. and also reason I mention in PM... but obviously only Frank can see that (and people who saw the original version of this post lol)..
Poor Mopar Bob been waiting a good 2 weeks for me to get back to him on some stuff to... some weeks so much free time, other weeks not quite as much :/

Where is the info at? I thought this would have been on here yesterday based on what you said. Although, no hurry....

BTW... I dunno if its the phone.... like my S5 can play 4k video's.. has multi core.. one of the most powerful phones available (it was.. probs not atm).. but maybe its an issue with the wifi card in it or something??? Anyways my dad just go an Iphone so I want to change my settings back to not working with 640x480 and see if it works on his iphone 6...
and do range testing... then apply my settings again.. and repeat range tests and also see how range compares to S5. Oh yeah did it work on Iphone 5? or 4?

How does the "droid" phone compare to S5 spec wise ?

640x480 really is so much more enjoyable to fly with.. even on a smaller screen like S5.

 

[Mopar Bob]

Justin, I have been messing about with trying to backup the original files from the RE and the Phantom. Been using winSCP. Problem I have encountered is that it will not transfer any symbolic links. Apparently linux knows what they are but windows does not. I was going to try and look into some type of image backup. Are you aware of a way of doing that? Image backup from Linux to windows? I do a weekly image from windows to windows to back up my PC and network and its fast and simple.

 

[justin00]

yeah.. use the tar command.. someone messed up there wifi module (doing something unrelated to this or what we have discussed) and needed someone to send them the entire filesystem.. so tar'd it all up and sent across.. was actually pretty small..couple of MB. Oh yeah tar has options you can specify for symlinks, but tbh in all of my tarring over the years i've never needed to play with the tar symlink options, but if you run into problems play around with the options.
Should even be able to tar/scp all in 1 command.

google how to create tar files and you'll find a ton of examples. very easy to do. was going to guess from memory but I can never remember if you specify tar file first or files to be tar'd. Let me know if you don't have any luck and I'll help.. but examples off google should be more than enough..

btw.. as your aware.. if make changes to wifi module or RE and something bad happens and cant reconnect obviously can't restore the backup.
Speaking of which.. been working of a script to solve just that problem (mentioned it earlier in thread few times)... basically as I mentioned earlier you add script to cronjob just before you are making critical changes (ones that can screw up wifi).. make your changes and reboot etc, if hostapd doesn't come back up or starts with critical errors, it will restore backup of your wifi config... its not 100% fool proof, so would like to keep adding more and more checks for it to do (to figure out if wifi is running or not).. Ultimately would love it to be able to check if its a) advertising its SSID and b) accepting hosts to join but that is abit beyond my programming skills, and Its solving a problem, which doesn't need *that much* solving... Espeacilly if you can find factory reset lol..
Let me know if you want to play around with that... I dare say it should not do anything bad.... worst case it wrongly restores your wifi backup and you loose 1 or 2 custom changes and have to spent 5 seconds changing them back.

 

[Mopar Bob]

btw.. as your aware.. if make changes to wifi module or RE and something bad happens and cant reconnect obviously can't restore the backup.

Yes I understand. That's why I was looking into the image backup. If I do an image restore on my PC, I don't reboot windows to do it. I was hoping there was a way to do the same in Linux. But I could be all wet on this idea. I'll do more research and see if I am way off target on this one.

 

[justin00]

There is.. but it would be incredibly complicated seems its cut down version of linux / openwrt.. the fact you have no console port just makes it 100000000% harder....
remember on your PC you have monitor/keyboard etc for windows restore.

I have another idea.. kind of a "dead mans switch" heh but an "alive mans switch"... hmmm or is it "dead mans switch" heh getting late.
Basically.. you modify your startup files to restore the critical config files if you do not login and MANUALLY intervene 5-10 mins after the system has come back up.

So you edit your file and make your change and reboot.. if something is screwed and you loose network, the process to save the day kicks in after 5-10 minutes, restores your files and reboots and all is good again.
If your change is good, you login and stop the process so the restore does not happen.

Its an ugly solution but is better idea than the script I have been working on. My script has a heap of ways it can let me down and fail...
Only given this 'alive mans switch' a few mins of thought, but the idea is growing on me.. I think I might revert to that... heaps less work than an automated script that does heaps of checks and the end result of alive man switch is more effective.

Anyways speaking of the console.. No serial port on the wifi module but I rekon a few pins or something must be hooked into a serial. On alot of other openwrt devices, or "custom" embedded linux type devices you can hook into the serial
by figuring out the pinout (usually just reading hardware specs). Unless I'm blind, DJI has that no where to be found.

2.10AM now so can't be stuffed taking phantom apart to look at wifi module... getting serial connection is going to bug me though heh so I'll probs spend some time of it.
I doubt there would be any point asking DJI how to tap into the serial :/

btw.. as your aware.. if make changes to wifi module or RE and something bad happens and cant reconnect obviously can't restore the backup.

Yes I understand. That's why I was looking into the image backup. If I do an image restore on my PC, I don't reboot windows to do it. I was hoping there was a way to do the same in Linux. But I could be all wet on this idea. I'll do more research and see if I am way off target on this one.

 

[Mopar Bob]

I doubt there would be any point asking DJI how to tap into the serial :

I agree but there has to be some way in because the code gets loaded initially by DJI. The question is how to figure out how DJI does it!

 

[general01]

I can't use the best quality here either and I know my wifi module is not vented

 

[justin00]

Quite a few diff ways.. I don't know much about electronic device production, but doubt it would be loaded in via the serial..
The interesting thing is... the tele data is piped in via the serial port and then outputted to TCP port 2001... So comes in via what the wifi module calls the serial, obviously from something in the Phantom then outputs to 2001 (so it can be read via the DJI App).. So sounds like the serial isn't going to connected to the console as is traditionally done... I'm still liking my "alive mans switch" :] I'm just going to stick with that.. I don't make all that many changes anyways... was just something to do to pass the time at work (all though others might find it useful)...

anyways will post up the settings I've used to get 640x480 in the next couple hours (yeah yeah I know been mentioning it for a few days know.. need to make sure I do it carefully as to avoid someone bricking it :/) Will be interesting to see the results people get.. I'm sure will be quite mixed in terms of range and if it even makes it usable for people with the same device (as in mobile phone).

I doubt there would be any point asking DJI how to tap into the serial :

I agree but there has to be some way in because the code gets loaded initially by DJI. The question is how to figure out how DJI does it!

 

[justin00]

Ok.. hesitant to post up.. don't want anyone to f' up there wifi units but.........


Ok Basically... simple change.. and a large portion of this is thanks for LinuxKid who told me about the HT40 change.. I just played around a little to find out what works best for me.. so big thanks to him

Now... do this at your own risk... If you have a mistype or screw up, or something goes wrong its possible you will not be able to connect back into the wifi module to fix, thus rendering the wifi module screwed and you will either need to buy a new one
or send back to DJI to get repaired.. If they even repair them.. I'm sure they can.. but if they do is another story..

This is an easy change, but not for someone not familiar with linux... Fark even using txt editor VI is pretty tricky hehe..

I would suggest anyone who wants to do this to read up on "HT40 vs HT20 wifi modes". From my understanding if you are in an area where you have alot of other interferance setting HT40 can actually give worse results than using HT20... Basically ht20 is the default and provides 20mhz channel.. Setting ht40 provides 2x20mhz channels and is kind of overlaps into other channels, thats why it can give worse results if you are in an area with heaps of wireless activity... which I am..

Odd thing is.. in my suburban area where I fly.. there are at minimum 10-15 other access points that I pickup, so in theory I should get worse results using HT40.. but yeah I don't... I did actually have to play around with the channel to get optimal results, but once I did (and few other settings its worked a treat at 640x480).

**** SO AGAIN... READ UP ON ALL OF THIS AT THIS SITE.. http://wiki.openwrt.org/doc/uci/wireless .... ITS GREAT.... THEN READ AGAIN ON GOOGLE... ****

I TAKE NO RESPONSIBILITY IF YOU BRICK YOUR WIFI MODULE... Also you need to read the site as there are some combinations of options/channels that will not work... I am not sure if you do this if the wifi module will not start up the HOSTAPD process (which basically runs the access point) will means the wifi module will not let you connect
or if it just still run hostapd but just complain/error, but still be useable...


There are a tonne of options you can change, and you can read about then on the openwrt site I posted above.. but I will just mention what I changed to get great 640x480 @ 30 FPS results..


so basically.. you ssh into 192.168.1.1 which is the phantom and have a look in /etc/config/wireless

You config will probably look like this


config wifi-device 'radio0'
option type 'mac80211'
option channel '6'
option hwmode '11ng'
option path 'platform/ar934x_wmac'
option htmode 'HT40-'
list ht_capab 'LDPC'
list ht_capab 'SHORT-GI-40'
list ht_capab 'TX-STBC'
list ht_capab 'RX-STBC1'
list ht_capab 'DSSS_CCK-40'
option country 'BO'
option txpower '17'

config wifi-iface
option device 'radio0'
option network 'lan'
option mode 'ap'
option wds '1'
option ssid 'FC200_01f825'
option encryption 'none'
option hidden '1'

Parts is bold, is what I changed...

So the first is the channel.. for me originally It was on channel 5.. Normally its good practise to run wifi or channel 1, 6 or 11... HOWEVER READ UP ON THE SITE I MENTIONED TO CONFIRM WHAT CHANNELS WORK WITH WHAT HT20/40 MODES..

So I changed first to channel 11 (from 5)... and I changed option htmode 'HT40-' originally this was set to HT20. There is mode HT40- HT40+ HT20 HOWEVER READ UP ON THE CHANNELS YOU USE WITH EACH MODE!!!!!!!!!!!!!!!!!!

Doing that I was able to run 640x480 @ 30 FPS for first time ever but the range sucked balls... so I changed it to channel 6.. That improved range quite a bit..
The second change I made was

list ht_capab 'SHORT-GI-40'

originally that was

list ht_capab 'SHORT-GI-20'

So I basically changed it from 20 to 40

And lol yeah thats it... Again I can't stress enough... read about what all the settings do.... HT40 may not work on all phones... so you may find your phone can not connect but hopefully your PC/Laptop can so you can change the setting back.

So in summary.. I made these changes

option channel '6'

the 6 was a 5, then 11 then settled on 6

option htmode 'HT40-'

original setting was

option htmode 'HT20'

last thing

list ht_capab 'SHORT-GI-40'

that was originally

list ht_capab 'SHORT-GI-20'


You may find just changing channels IS ALL YOU NEED TO RUN AT 640x480 @ 30FPS!!!! without the ht20/40 stuff
Or you might need to change to HT40... or you might need to change the SHORT-GI-40 setting.


Some of you may find changing all of it a) makes it 640x480 work nicely... b) doesn't make any diff and same as before... and worst case c) bricks wifi unit.

Can't stress enough.... if your not familiar with linux have a long hard thing about if this is worth it... if things go bad I mean....



Again, big thanks to Linuxkid who initially steared me in the direction of HT40 which then led to me optimizing slightly and finally getting 640x480 @ 30FPS mode working...

As some of you said... seems to work on some phones... but not 98% of them though... anyways I have put the changes I described into my mates vision + (non v3) and now 640x480 @ 30FPS works great on his Samsung S4, and my vision + (non v3) works great on Samsung S5.
Another friend who has a vision + and a Samsung s5 (same android version as mine) we left default of ht20 on... but we changed from his default channel 9 to channel 6 and he was able to run 640x480 @ 30 fps.. which is odd!!! but yeah just a channel change was all that was needed/

Oh yeah I have the tx power boosted to 17dbm as well... but I found initiallly 640x480 @ 30FPS and even 15 FPS doesn't even work from like 3 feet away lol.. so any boosting can't fix that.

BTW The changes made on the phantom in /etc/config/wireless are for the HIDDEN ssid that the RE connects to.... the RE then runs another SSID called Phantom_xxxx which your device connects back to... problem is if hidden SSID on the wifi unit in Phantom is screwed, you device will not be able to connect to RE.. and even if it coudl.. the RE could not connect lol... so yeah....

Oh yeah you can ignore the country code and txpower setting in my /etc/config/wireless... It is not how you change the TXPOWER, I was playing around with that a while ago and just never took it out... the commands used to work, possibly on phantom vision (non plus???) I dunno, but aren't suported on vision plus, to change your txpower you need to do other stuff..

***

If you guys want I can provide my script which does some checks.. so if you make the changes and if something f's up and you can not connect back into the wifi unit... the system will automatically restore the old wireless config and fix it up.. this saving you from bricking the unit

***

As I said.. only a few changes.. but a lot of reading needs to be done before deciding if you want to go through with it... maybe I am just a bit dramatic.... i dunno.. I've been using linux for 15 years... and I was kinda scared each time I did a reboot lol..... I must say though 640x480 @ 30fps is very clear :]

and again.. thanks to Linuxkid!!!!

 

[justin00]

oh yeeah lol... make each change you want and reboot phantom.. (can either type reboot or power cycle)
best to try 1 setting at a time, see the results you get.... otherwise you don't rreally know what did what to fix or make worse etc etc.

 

[Mopar Bob]

I have one suggestion before anyone makes any changes. That is to make a copy of the file before making any changes. Just in case you have issues with vi and want to revert back to the original file. Use the command "scp /etc/config/wireless /etc/config/wireless_copy" and reverse the command to recover.

 

[justin00]

I think you mean "cp" and not "scp" ?

cp copies a file and scp is used to move it to a remote server, usually.

 

[larsmars]

Isn't it better that you install the WebUI of the phantom first .
http://phantommods.info/install-webui/
and do the changes via the WebUI

Lars

 

[justin00]

Never tried the GUI; However from screenshots I have seen I didn't think it lets you change some of the options I am referring to. Thought it just lets you change channel, power, encryption and that sort of basic stuff ? I might be ofcourse wrong... /