Release blog on Ardupilot blog

[Georacer]

@hunt0r Here's a proposal for the release blog. All suggestions welcome.

Hello everyone! 1.5 year ago, me and @hunt0r needed to parse some ArduPlane logs. We are both on our track to get a PhD in UAV control systems and Matlab is a very common tool in our trade.

Sadly, at the time the only tool able to convert from DataFlash logs (.bin) to a format readable by Matlab was Mission Planner and it didn't do a good job at that. It would work only on Windows, take a very long time to convert and would ignore all text fields.

So, we decided to create our own converter, ardupilog. It is Matlab-based, meaning that you need Matlab to run it. It can read all DataFlash logs, since they are self-defining, and create a versatile log object. You can even "flatten" the log into a classic struct, if you want the information to be independent of our library.

Example Usage

Reading a log

Add the ardupilog source code to your path. Then,

log = Ardupilog()

will open a file browser, where you can select the log file you want to decode. The variable struct log will be generated with the included message types as fields. Its contents can be normally processed with Matlab commands: << Placeholder for images of the resulting struct and a plot >>

Filtering messages

You can optionally filter the log file for specific message types:

log = Ardupilog('<path-to-log', <msgFilter>)

msgFilter can be:

• Either a vector of integers, representing the message IDs you want to convert.
• Or a cell array of strings. Each string is the literal name of the message type. << Placeholder image with filtered log >>

Slicing

Typically, only a small portion of the flight log is of interest. Ardupilog supports slicing logs to a specific start-end interval. For example, to keep log messages from boot time 1000sec to 2500sec:

sliced_log = log.getSlice([1000, 2500], 'TimeS')

<< Placeholder image with sliced log >>

Exporting to plain struct

Creating a more basic struct file, free of the ardupilog dependency, is possible with:

log_struct = log.getStruct();

log_struct does not need the ardupilog source code accompanying it to be shared. << Placeholder image with plain struct >>

More information can be found on the repo's README.

[Georacer]

Do we want to have a uniform format for the Ardupilog name? Possible options:

• Ardupilog
• ardupilog
• ardupilog (in italics)
• ardupilog (in true-type) Is anyone of your fancy?

[hunt0r]

For the name: I slightly prefer it capitalized (coming from MATLAB's convention to capitalize class names, I think) and I think the true-type looks nice too, if that's easy. But I'm okay with something else if you like, it doesn't matter much to me.

For the blog-post announcement, I noticed a few tiny grammar things that I would change: 1) I prefer not starting sentences with numbers, so I'd replace ("1.5 year ago, ...") with either "About a year ago ..." or maybe "About two years ago..." If you like to be more specific on the time, "A year-and-a-half ago, ..." 2) Two minor grammar formalities: When listing other people and yourself, it's considered proper to list yourself last. (So change "me and @hunt0r" to "@hunt0r and me") But also, since we are the subjects of the sentence (not the objects) you should use "I" instead of "me". So I propose changing to "A year-and-a-half ago, @hunt0r and I needed to parse some ArduPlane logs..." 3) When talking about Mission Planner, can we avoid the possibility of insult by changing "it [Mission Planner] didn't do a good job" to something like "it didn't serve our needs well enough." 4) Is this a good place to mention a "wishlist" item that someone else might code for us? The major one that comes to mind: I wish Ardupilog could also encode .tlog files to a similar MATLAB format. But I'm not willing to implement it myself.

Overall, it looks great! What else might I do to help?

[Georacer]

Thanks a bunch for the corrections!

Regarding the wishlist, I think we have it already laid-out in the Issues page, as feature requests. I'll pull 2-3 of the most notable and put them in the blog post.

[Georacer]

Posted here: https://discuss.ardupilot.org/t/ardupilog-a-dataflash-log-to-matlab-converter/33812 Close this if no more edits are needed.

[hunt0r]

It looks outstanding. Thanks so much for that!