Tlog plugin

[vooon]

Plugin to write fcu message logs.

[TSC21]

I totally recommend a bridge to FlightPlot: http://pixhawk.org/dev/flightplot and pymavlink: http://pixhawk.org/dev/pymavlink

[vooon]

Ok, i'll see this. Log plugin not highly required (because FCU also has it's log, and GCS too), maybe easies way it use rosbag on /mavlink/from.

[TSC21]

The importance of this bridge is the possibility of direct access to .bin files on the sdcard and get them to FlightPlot or pymavlink, which are already prepared to read the .bin log files.
Doing the same thing to rqt_plot would be awesome though :D

[TSC21]

A good tool to plot trajectories: https://code.google.com/p/streamvis/

[TSC21]

I also may give a try to rosmatlab bridge (https://github.com/tu-darmstadt-ros-pkg/rosmatlab) and see if I can get the pose plotted in 3D like this: https://dl.dropboxusercontent.com/u/12446150/SE3_TRJ_Plotting.zip

Related:

• http://www.qgroundcontrol.org/users/matlab_import
• https://github.com/fedeDev/mav2simulink (needs a mavlink msg handler update though)

[TSC21]

One more thing: to have access to the log files: http://www.qgroundcontrol.org/mavlink/ftp, which means a FTP protocol communication on mavros side.

[vooon]

FTP now not very stable, currently better use QGC for it.

[TSC21]

QGC uses the FTP to download the log files. Something on ROS side I believe it's possible to do also.

[TSC21]

@vooon I really would like to give a try at this, but you have to help me regarding the FTP side. It's already merged onto PX4 master and working with GCS.

This could be great to download the .bin/.tlog/.log files from the SD card and use them to check out logs on FlightPlot, pymavlink or even rqt_plot (we just need to find a way to get this kind of files read by rqt_plot).

Another good thing to do is printing the .bin/.tlog/.log in the terminal using rosconsole.

It will require some days of work but I think we can manage to get something good of this.

Note: the related msg is FILE_TRANSFER_PROTOCOL. And here's the QGC side: https://github.com/mavlink/qgroundcontrol/pull/658/files.

[vooon]

Wait some time. Current implementation use ENCAPSULATED_DATA message. I think FILE_TRANSFER_PROTOCOL incomplete: they can extract message header from data filed.

[TSC21]

Where have you found that info? Probably ENCAPSULATED_DATA is the msg to be used.

[vooon]

It you look into the code, you found that every FTP message contain header, that can be moved to mavlink message.

In addition, I do not like that the FTP interferes with image streaming.

[TSC21]

So what's the best option? That interference with the image streaming may be normal so it can get better download speeds.

[TSC21]

Regarding reading (or writing) from files: http://answers.ros.org/question/128891/how-to-read-and-writing-ros-message-efficient-into-files-c/. This way we can publish the content into rosconsole or into a topic with several fields that can that can be subscribed by rqt_plot (custom msg required).

Since you say to wait for FTP to be more stable, we can start by creating a srv to read log files and get them showed on terminal or published in a topic.
Something like:
rosrun mavros log read </path/to/file> to_terminal
rosrun mavros log read </path/to/file> to_topic

[vooon]

I decide just use rosbag.

Example launch:

<launch>
    <!-- vim: ft=xml -->
    <include file="$(find mavros)/launch/apm2_radio.launch">
        <arg name="gcs_url" value="tcp-l://" />
    </include>

    <!-- log all data for now -->
    <node pkg="rosbag" type="record" name="rosbag" args="-a" />
</launch>

[TSC21]

@vooon you are making a confusion between the current logs and the logs that come from sdlog2, which are stored in SD card as .bin. If one doesn't have a telemetry radio, can't log files that way (in my case for example my 3DR module broke down after a crash :/ )

[vooon]

I use APM 2.6 on bixler, so it hasn't sd card, only DataFlash 4MB chip.
So i can get logs from FCU using MissionPlanner.
Additional i write telemetry logs on ground by GCS and mavros.

Initional this issue about writing logs by mavros on ground computer, and i solve it using rosbag.
Gcs tools don't know bag format, but i can play telemetry stream via gcs_bridge.

[TSC21]

OK then. So I think we can move to #138, which is prety much the same but tends to get log data to terminal.