Hi, folks – it seems that there are 3 possible MAVLink routers available in BlueOS: BlueOS Documentation
Are there any further docs on this? For example, I don’t see pros / cons of using MAVLinkRouter (the default).
As we switch to Cockpit, it is super-important that we pick a router that will generate telemetry logs. It seems like MAVLink-Server is the new hotness, so we’ll test that next, but I wanted to double-check to see if there are other parameters to consider.
Thanks!
Hi @clyde -
From what I understand, the Blue Robotics software team was not liking Mavlink router and MAVp2p, so developed Mavlink server - this is the default on 1.5 beta versions. To a user, they should all behave the same, but I believe under the hood Mavlink server is setup for better performance and will be the Blue Robotics standard going forward. In some limited cases, communications issues have behaved better with Mavlink server!
By generate telemetry logs, do you mean .BIN or .TLOG?
Hi @tony-white – I meant tlog files. Thanks for the info!
@tony-white @clyde should the Mavlink server create tlogs by default? I ask because after an ROV flight we can see a generated .BIN file in the Log Browser folder on BlueOS, but we have not been able to find the corresponding .tlog file. I am also not seeing any new .tlogs in File Browser > ardupilot_logs > logs. However if I run QGC (v4.5.0), I can find a telemetry log in the telemetry folder for QGC in our File Explorer.
The .tlog files are of particular interest to us, as that is how we gather time-coded telemetry data.
We are running:
Thanks in advance for your help!
Hi @m.williams -
I would hope yu mean BlueOS v1.5 beta 37? The version you list does not exist…
It’s also worth updating to he latest version of ArduSub?
I don’t believe Mavlink server creates tlogs, but will check on that. In general, you should be able to collect any telemetry you need from the .BIN files, or other means like an extension or script you run locally during operation? What sort of data are you working with / can you share more about your application?
@tony-white I do indeed mean 1.5.0-beta 37. Sorry about that, still working on my coffee this morning.
I work on the Seattle Aquarium’s ROV team. We are using a BlueROV2 to survey nearshore marine habitats, mainly kelp forests. Surveys are optimized to collect high-resolution, georeferenced imagery to support analyses of seafloor composition, kelp and algal cover, and associated benthic communities.
We are capturing the seafloor with GoPros, which are time-synced to the ROV laptop, so we can georeference the images using the telemetry logs. From the tlogs, we gather depth, altitude, speed, power consumption, and coordinates based on global (satellite compass on the vessel fed to WaterLinked GPS) and local (DVL movements) positioning. You can find our script to convert tlog files into workable csv files here.
From the .BIN files, we have indeed been able to gather this type of information, but it is not time-synced with the laptop. It appears the .BIN files record time since boot. We haven’t been using that since we record the start and end times of surveys in the field and use those to clip transect telemetry and imagery. Using our methods, the only way to tie the GoPro images back to the telemetry data is by using date/time information.
Is there a way to extract relevant time and date information from the .BIN files?
Hi @m.williams -
Thanks for the context!
No way to extract time in .BIN logs I’m afraid. However, BlueOS 1.5 creates .mcap log files (see recorder tab in left menu) - these can be viewed with foxglove, or processed via (updated versions of your) scripts to extract the information you’re after - the same as the .tlog would capture!
Great, thanks @tony-white ! We will download those files and update the scripts accordingly.
If anyone is wondering where these files are located, we found them in BlueOS by going to the “File Browser” and opening “userdata/recorder”.