Just curious to know what people are doing to maintain a somewhat accurate time on the RP4? It looks like the RP4 get’s it’s time from the internet by default. If you’re offline, out in the field, then that isn’t going to work.
You can purchase a realtime clock module add-on for RP4. These seem to plug in to the bus header, which is taken up by the Navigator.
We could set it up to synch to a time server on the top-side computer - but our direction of travel is ideally to dumb down the topside to something like a ruggedised tablet… So not sure if we can do that.
What are people using to get reliable, battery backed, time on the BlueROV2?
Hi Peter -
A RTC has definitely been discussed for future versions of the Navigator, as well as PPS input and Precision Time Protocol support at the kernel level. For users with 4G cellular internet connections (BlueBoat), the NTP time sync you mention is pretty good- as is the time from the GPS. I often dive my BlueROV2 with it having an active internet at the start of, or even the duration of the dive.
With the header occupied, I would think a USB RTC could likely be supported with minimal software effort?
Just an updated to this thread… Turns out that if you have a surface GPS installed the time seems to miraculously get set correctly, presumably based on the GNSS message received (?). So that’s cool!
Our only challenge then is making sure our 2nd Raspberry Pi (RP5) - used for the downward looking camera - has time synch with the primary Raspberry Pi (RP4). Let me know if you have any recommendations on this. We’re playing with NTP and Chrony…
Hi @PeterM -
Yes, you’ll find BlueOS will sync time to GPS as well as when it has an internet connection. You could have your Pi sync to internet time, if a connection is available, but I would imagine it must be possible from the BlueOS Pi somehow!
Another approach would be to use the same Pi 4 for the downward looking camera. I’d assume it is a USB module, perhaps the ExploreHD from DWE?
Cockpit supports streaming the video and recording it, or you could develop an extension that uses gstreamer to record the video stream locally - I’m actually just starting to fiddle with this for a BlueOS drop-camera project.