tejones777
 lvl.1
United States
Offline
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Okay, I think a lot of people are confused by the FLIGHT LOG files. This is confusing for a number of reasons, but please let me tell you what I know.
First, there is a log file that is written during each flight onto the PHANTOM 3 itself. It is possibly written to that "secret" microSD card that you can see if you look into the phantom 3 battery compartment, just under the phantom 3 motherboard. Those files are named FLY???.DAT or something similar, and are a binary file, that so far, there is no software, other than in-house software at DJI where the DJI technicians read the files, and can tell if you caused a crash, or if the phantom crashed due to a warranty bug. If you complain that your phantom fell out of the sky, with no warning, and not because of your fault, the DJI support technicians will ask you to send them the last 3 files to them, and they will decode them, and find out if it was operator error, or if the phantom malfunctioned. It's sort of a black box recording. This may actually be encrypted by a java-encryption algorithm, which is slightly different than the usual NSA encryption algorithms, and if you search the internet, and DJI Phantom/Inspire technical forums, you'll maybe even see some talk about them. Note, that DJI over the years has made many products that generate DJI files, namely the *.DAT files made by some iOSD device, and those DAT files have a program called "data viewer" or something like that, which has been released in various versions (I have 1.1 and 1.4) but that data viewer program doesn't seem to read the Phantom 3/Inspire FLY???.DAT files at all. Don't go through all the trouble of finding those data viewing programs, they just won't work. One more thing, for these *.DAT programs, I'm not certain they are actually encrypted. There is a rumor that they are encrypted, so that DJI, and only DJI, can read them, and find out what black-box info they contain. It's been said that will keep users from "faking" a *.DAT file showing the phantom crashed through no fault of their own, or could be so law enforcement could ask DJI to decode information from a phantom used in illegal activity, to find out lots of the secret information about where it's been, and what happened. But there is one forum entry which shows the FLY???.DAT files actually has just CANBUS packets from the various sensors and controls, and is not encoded. I kinda believe this, because if you "strings" the *.DAT files, you can see little bits of readable information, instead of random bits like you'd expect if it was encrypted. I certainly hope, at some point, someone can decode and use these *.DAT files, as they are the most important.
Now to get these *.DAT files, you need to go into the DJI PILOT application, and go to settings, and there's a place where you can turn on "flight log access" or something like that, which puts your phantom into a funny mode, where the gimbal beeps and looks down, and then if you plug a USB cable into the microUSB port under the rubber flap on the front of the phantom, it will look like a thumb drive full of all of the FLY???.DAT files. But of course, I know of no program that can read these, and their only confirmed use is the send the last 3 of them to DJI if you're hoping to get them to buy you a new bird (but most likely, the best you'll get is a 30% discount off your next Phantom.)
Okay, that's the *.DAT files on the phantom itself.
Now there's another, much more usable log file, called the *.txt files. These are on your tablet (android or IOS) and are under the directory for DGI then the subdirectory DJIPILOT then the subdirectory of FLIGHTRECORDINGS or something like that ("DJI/dji.pilot/FlightRecord" to be more specific.) The IOS people are often having problems finding these files, as apple products don't have a lot of software allowing you to hack into the internals, but they're easy to find on android tablets/phones with a simple "FILE" reading utility (one comes free with all android devices.) Now these recordings, named *.txt, are the ones that the "FLYLITCHI" program on the internet can read, and convert to a comma separated data file (CSV) which actually is formatted well enough you can use it with DASHWARE which adds your telemetry data to the video. The postings about the FLYLITCHI converter (http://flylitchi.com/logs) suggest this *.txt file not only has GPS data and time, altitude, speed data, but a huge amount of telemetry information, including gimbal positions of the transmitter, to prove if you've been causing the Phantom to crash, or if it just spontaneously crashed. It's a huge file, so I'm not surprised. It seems from the postings, that there is a ton of information in those *.txt log files.
Now, the DJI pilot application on your phone/tablet seems to probably read these *.txt files, but maybe it reads the FLY?????.DAT files, and prints telemetry, and maybe even gimbal (control sticks on the transmitter) information. Actually, the Android version of DJI PILOT (currently 1.1.0, I think) does not show the position of your transmitter gimbals, but the IOS version (currently 1.1.1, I think) seems to show the positions of the transmitter's gimbals, as it plays back the flight log. I don't know if DJI is trying to reward those poor Apple customers who couldn't fly their Phantom due to a missing IOS application, or if the next update of DJI Pilot for the phantom will also have this transmitter position display, but for now, Android users don't get the full program capabilities.
The people who made the flylitchi log converter, apparently aren't divulging their secrets on how they are reading the *.txt files, to pull telemetry information out. They probably have plans of incorporating that into a profit making product, as they make some Phantom-3 flight software already, and I'm sure would like to get a bit of payment for all their hard work.
If I'm wrong about this summary of the "secret log file" information, please let me know. More details about the secret microSD memory card in the battery bay, the flylitchi converter, and the other gobs of information in the *.txt files, and the FLY????.DAT files on the phantom, can be found on searching this or the several other forums. (PHANTOMPILOT and RCGROUPS.)
I'm seriously hoping someone, somewhere, will come up with a FLY????.DAT file reader, or that someone will come out with a good *.txt file reader (not online, and not limited to the few data pieces that the flylitchi converter shows. Supposedly, the data format information for the *.txt files is in the SDK for the phantom 3 (or inspire?) so anyone who has access to that, could make a simple data converter.
- tj.
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