Some time ago having so called one beer too much I’ve promised that I will make the “ocean project” I was think about Bristlemouth compatible. Well, 4 times more time that I’ve expected later there she is:
Probably rather basic thing and similar to Bristlemouth Mote. The board in the middle is 10Base-T1L header based on the same IC the Bristlemouth Mote uses, therefore it also has two ports and it should be possible to chain the nodes. The board on the top is the power over data line extension, has a current sensor, 5V DC/DC converter to power the RPi and gives “VBUS” out.
It can probably simplify building things like underwater cameras, acoustics, etc. for the price of being more power hungry than Spotter and Bristlemouth Mote.
Looking at the 2-conductor connectors from this angle from the photo makes me doubt if the part Zach suggested might fit into the parts placed on your boards. Maybe I can help suggesting a different cable if you could share the part number of the part you have used.
@umakat: Yes, those are 43650-ish Molex micro fit connectors, horizontal and vertical. I think the one which Zach mentioned are used in BM Mote, which may be better if it would not fit here because I think the polarities are conveniently reversed.
I think I eventually figured out how to assembly those Molex plugs, or at least seems that every 10 tries I’m able to get one plug done right (I think I start to understand Molex’s business model).
@zachary: about the software, it’s probably the time when I should start to consider myself old and stubborn but all the tests I’ve made so far were done on a good old Debian (not to confuse with, I believe, Debian-based Raspberry Pi OS).
I think that’s actually the most important part, because it works almost out of the box with a regular Linux, it should be possible to get two of those, connect an external wifi adapter/antenna, battery and solar panels on one end, a camera/hydrophone on the other and if you are in the wifi range you can have an underwater live video/audio stream running in one weekend.
Hi @luk, great work! I would love to test this setup. We’re playing with a bunch of different sensor integrations, an alternative to the Mote would be great and running on Debian opens a world of possibilities.
Do you have any reference material that you are willing to share? Schematics and such, or a sample board that we can purchase?
I have 3 sets like this at the moment, two should be relatively “reliable”, the third one took some “rework” so I wouldn’t trust it too much, but for testing something in the lab should be good enough. I can just send them over .. a pioneer program
It should be similar to Bristlemouth Mote and meet most of the Bristlemouth spec. In theory those two should be able to talk to each other.
Some key differences would be:
*) mentioned reversed polarity of molex connectors
*) the current sensor is placed differently, it measures power the board draws from/feeds to VBUS, not the pass-through
*) I’ve skipped adding a separate 1.8V DC/DC converter
*) I think the components have bit higher ratings, in theory it should be possible to push up to 1.5A at 30V over PoDL
*) 5V DC/DC converter should support solid 3A
*) there are few “jumpers” to tweak things
Brilliant, thank you @luk!
I’ll sit with my nerds and brainstorm some ideas for testing it in the wild.
If you have a schematic that we can look at so long that would be very helpful.