Anyone looked at Shearwater CANBus Protocol?

[telemonster]

In similar scenarios, I've been able to insert the ends of wire-wrap wires (i.e. insulated, stripped, very fine gauge) into the female sockets, and hold it in place while plugging in the male connector.

Ah interesting! The thing is, I don't want to do anything to hurt the integrity of the connectors and I would be afraid even thought he wire is super thin, I could end up deforming the walls of the pins. And then water could get in. Also, the connectors disconnect with a solid pop noise which is really cool.

Another option is to open the head again and make a cable that sits in between the PCB there and the molex or JST connector that comes from the cable. I am hoping to go a route that is A) Easy and B) does nothing to hurt the integrity of any of the connectors.

 

[lairdb]

OK, I pulled the (fairly simplified) CAD models and looked -- it appears there's not really a liquid-tight connection, it's just the relatively soft rubber and an interference fit, so I get your concern about distortion.

FWIW, if you haven't already: you could do it on the benchtop by clipping to the male pins and using a substitute similar 2mm dia pin into the female ends, as long as it reached in far enough:

ETA: connector brochure.

 

[MaxTorque]

CAN is a very simple protocol and it is extremely unlikely that Shearwater have attempted any data encryption. You advantage is that you can see data values on your normal displays, so all you need to do is to log the CAN bus whilst you cause a known value to change, and then look at the data to see if you can find that value in the data!

Assuming they are running basic CAN 2.0 and not CANFD (FD = flexible data rate), then the baud (bit rate) is fixed, and message payload is also fixed at 8 bytes / 64 bits

The easiest way to get started is to buy a cheap CAN-> USB dongle for example the PEAK CAN dongle, and use the basic free software supplied to record the CAN messages to your computer. Peak and Kvaser (the two largest CAN test equipment suppliers in the market) also both have a free Windows APi meaning if you can write software (for example using visual studio) then you can easily develop your own logger

 

[rjack321]

Started trying to poke at this last week. So far I've established pin #1 (which is the center bottom pin on the 5 pin connector) is tied to system ground.

The next issue I have is the connectors used. They're pretty sexy, but in my mind I could back it out part way and access the contact to clip on. Turns out it's not the case (I rarely disconnect my handset and hud from the head.)

I found the connectors that they use I believe, wet mate MCIL-5F and MCIL-5M. So far the pricing for the connector alone seems to be in the $80+ range each. Whooo bum stinging thinking about that one. They're use in a few applications so I will either hunt for an extension cable that can be sacrificed or maybe look at 3d printing something and using some nice pins.

I'm only looking to sniff the read-only hud side.

You might be able to scrounge up some dead EO connectors. The female side is the side that dies from corrosion, the male side is usually fine. Snip off the pin and solder on your own wire as a test connector. Looks like the pins are the same size even if the EO only has 1 male per connector.

 

[tbone1004]

@rjack321 not EO compatible

 

[joshk]

@telemonster I'm curious if you found anything here