Accessing the P2 wifi repeater and camera

[MonsieurAnon]

Ohh, I thought that the camera was basically self contained, and that the wires were for power and for GPS data only.

Are you talking about the regular Vision or Vision+, or both?

 

[seaowl]

Yes, Vision camera is self-contained, but this topic is talking all about P2V+.
PV2+ (vision+) carry a Wifi module inside the bird, and camera on the gimbal.

Btw, I have phantom2 vision+ schematics 70% done

Please is there anybody who can help to describe this signal ?
It is PITCH control connection from WiFi module to the gimbal.
What protocol is it? Is it UART (ser2net) signal or not? Signal gurus I need your help!

Post update: Connecting a simple UART TTL USB converter, I found that it is UART protocol, need some decoding work.

 

[seaowl]

If you get this error

root@Phantom:~# opkg update
Downloading http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/Packages.gz.
wget: server returned error: HTTP/1.1 404 Not Found
Collected errors:
 * opkg_download: Failed to download http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/Packages.gz, wget returned 1.

Read this https://forum.openwrt.org/viewtopic.php ... 43#p243943
Old config (does not work):

src/gz chaos_calmer http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/Packages.gz  )

New config:

src/gz chaos_calmer_base http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/base
src/gz chaos_calmer_luci http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/luci
src/gz chaos_calmer_management http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/management
src/gz chaos_calmer_packages http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/packages
src/gz chaos_calmer_routing http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/routing
src/gz chaos_calmer_telephony http://downloads.openwrt.org/snapshots/trunk/ar71xx/packages/telephony

As for me, opkg update worked only with installing Fiddler (opensource proxy for programmers) on Windows PC, and setting proxy option in /etc/opkg.conf

option http_proxy http://192.168.1.xxx:8888/

 

[seaowl]

Yes, Sirs, it is UDT protocol.

 

[Ghostrider]

Good find! That explains why my UDP efforts looked right but just didn't work.
UDT though, huh? I don't remember seeing this BSD license anywhere...http://udt.sourceforge.net/LICENSE.txt
Just tried to view "Terms and Privacy" in the DJI Vision app but there is no action on the button...
I'd think University of Illinois would be promoting the video capabilities of their project a little harder if it was the core of the leading consumer UAV platform...maybe they don't know either!

 

[seaowl]

Android APK decompilation is amazingly easy. It can help all good people to get more from Phantoms

Steps to dig into source code for DJI Vision App:

Download DJI Vision APK file
1. Install DJI Vision application at Android tablet/smartphone
2. Install APK Extractor (https://play.google.com/store/apps/deta ... com.ext.ui), open it, and select "DJI Vision", then press Extract button
3. APK file is extracted to \Phone\ExtractedApks. Download it to your computer

Extract APK file to a folder
4. Unzip DJI VISION_com.dji.vision_1.0.52_52.apk with your favorite utility for file compression. I use WinRAR.
5. Install dex2jar tool (https://code.google.com/p/dex2jar/), run it, and convert classes.dex to classes_dex2jar.jar

Decompile JAR and have fun
6. Get Java Decompiler (jd-gui.exe) from http://jd.benow.ca/, and run it
7. Open classes_dex2jar.jar from it, you will certainly see lots of interesting info! :geek:

Have fun!

 

[Ghostrider]

Here are all APKs for all versions if you want to skip the first part or dig into a certain changeset.
http://droneslinger.com/software.html

 

[seaowl]

Thank you for a link, Ghostrider!
Btw, they use native (armeabi) libs, so we need to deal with some additional tools.

C:\dji\apk\DJI VISION_com.dji.vision_1.0.52_52.apk\lib\armeabi>
libamapv302.so                    
libamapv302ex.so
libapp_BaiduMapApplib_v2_1_1.so   
libcom_google_ase_Exec.so
libDJICam.so                     
libdjivideo.so
libFlyForbid.so                   
libGroudStation.so
liblocSDK3.so                     
libvi_voslib.so

 

[Morgon]

seaowl, I don't know if you already have a better method for this (e.g. IDA Pro), but if not, I'm curious if you could get any useful output from one of those .so's (probably libDJICam) at http://decompiler.fit.vutbr.cz/decompilation/ -- This was suggested on a StackExchange question about R-E/decompiling .so files.

 

[justin00]

Hmm interesting.. so the phantom runs an AP with hidden SSID (Fc2000_xxxxxx if i remember right from earlier in the night) which extender is client to... and the extender then runs an AP which your phone/device is client to and extender then bridges the 2 together right? I suppose if your phone had a fancy antenna you could connect directly to the phantoms AP and bypass the range extender all together? You'd need to set static IP on phone or modify dhcp server on Phantom though..

 

[seaowl]

Smartphone antenna is not as good, as build-in directional antenna inside a Wifi Access Point is.
I tested a 2-3 km distance now, Wi-Fi video is excellent, with home-brew extender.
I tested the Ubuquity access point, the TP-Link 5210 access point, and Mikrotik wifi router.
All this 2.4 wifi devices worked great with DJI Phantom2 Vision+.

All you need to clone a wifi extender - is to configure 2 wifi interfaces in a bridge.
Interface#1 is configured as a client for hidden phantom SID (scan QR code to know it, or write it down from the DJI App)
Interface#2 is configured as an access point with any name (I prefer just "Phantom_extender")
Put this two interfaces in a bridge, switch phantom on, connect your smartphone to a "Phantom_extender" net, and have a fun with long-distance video going via powerful wifi access point.
Don't forget to switch off a factory "wifi extender" it is not needed now.

 

[didier4r]

Hello from france.

I try to copy pictures from the sdcard to my computer without removing it from my PV2+, and without connecting the usb cable. Just using the WiFi.
Because the cable is not easy to plug, and I have no card reader on my desktop.

When I ssh 192.168.1.1, I cannot find anything in /mnt/sda1 (empty directory)

verygreen wrote :

- another web server on port 1026 - This one you use to access pictures from phone app.
* When you go to "Album" apge in the app, it sends a control signal to the camera and camera enters "usb storage" mode, becoming visible as a usb flashdrive to this ystem that is then mounted to /mnt/sda1

Anyway, if you need to download the files, including dmg - you just need to enter the "Album" mode from your phone app, and after that use ssh from your computer to get content of /mnt/sda1. Use any number of freely available windows ssh clients, or openssh is already shipped with MacOS out of the box.

But even displaying pictures on my mobile dji vision app does not help : /mnt/sda1 is still empty under the ssh connection.
And using 192.168.1.1:1026 does not show anything on a web browser.
What am I missing ?
Thanks in advance.

PS : I've successfully installed luci on the repeater and the drone - thanks to linuxkidd. Great web interface.
I'll try again, browsing first the album from my mobile, before using ssh ...

 

[linuxkidd]

Hello didier4r,
If by any chance, you were already cd'd into the /mnt/sda1 directory *before* it gets mounted (by the browsing via android app), then you'll continue to see the empty directory. You should be able to do something like:

cd /
cd /mnt/sda1
ls

And then see the contents.

Hope this helps,
LK

 

[didier4r]

Sorry for my stupid question : as written, I had to browse the album before using the ssh command to enter the DCIM folder.

One last question : how do I transfer files from the drone to my computer ?
I have tried scp -r [email protected]:/mnt/sda1/DCIM/100MEDIA/ 192.168.1.187/home/me/mypictures
It does not work.
192.168.1.187 is my ip given by the drone dhcp, mypictures my destination folder.

 

[linuxkidd]

From your local PC (running Linux or Mac I presume), you could just:

scp -r [email protected]:/mnt/sda/DCIM/100MEDIA/* /home/me/mypictures/

LK

 

[didier4r]

Thank you very much, linuxkidd, I'll try tomorrow as it's late here and I must get up early tomorrow.

 

[didier4r]

Everything is easy with your help !
Copying with the WiFi works great

Does someone know how to send the mounting command (without using our mobiles) - we could then very easily write a script with 2 choices :
- a simple copy from all files on the sd card to our computer
- a copy followed by a rm (remove) commande on the sd card to empty it
Automation is sometimes useful !

Ps : yes, i'm running Linux, but I'm also using a Non Linear Video Editor under Windows.

 

[madfrenchie]

Has any work been done on decoding the video stream?

I've always wanted to be able to run the Phantom 2 Vision plus from my PC,

I'd like to use something like base station on the PC, but without having the additional hardware. I'm sure it wouldn't be too hard to figure out how to get Base Station to work though the wifi connection of your PC.

 

[linuxkidd]

There are a few threads discussing this in other sections of the forum... sorry I don't have links to them off the top of my head, but a search either with the forum's built in search, or using google like:

sitehantompilots.com decode camera stream

Or similar... should return some things...

LK

 

[John Abbey]

Smartphone antenna is not as good, as build-in directional antenna inside a Wifi Access Point is.
I tested a 2-3 km distance now, Wi-Fi video is excellent, with home-brew extender.
I tested the Ubuquity access point, the TP-Link 5210 access point, and Mikrotik wifi router.
All this 2.4 wifi devices worked great with DJI Phantom2 Vision+.

All you need to clone a wifi extender - is to configure 2 wifi interfaces in a bridge.
Interface#1 is configured as a client for hidden phantom SID (scan QR code to know it, or write it down from the DJI App)
Interface#2 is configured as an access point with any name (I prefer just "Phantom_extender")
Put this two interfaces in a bridge, switch phantom on, connect your smartphone to a "Phantom_extender" net, and have a fun with long-distance video going via powerful wifi access point.
Don't forget to switch off a factory "wifi extender" it is not needed now.

Just diving into this now. Great work. So, do I assume that you'll need the ser2net configuration copied into place as well? I assume those serial connections to the Phantom's WiFi are required to get telemetry data correct?