How to connect a Raymarine SeaTalk bus via the bbn-m5-s3-n2k-usb setup.

[jwensas]

Hi,

I think I've officially ran aground in my attempt to connect my Raymarine SeaTalk N2K network to my Pi-5 running BBN with the bbn-m5-s3-n2k-usb setup.

I don't see the M5AtomS3 change it's blue blink so apparently no data is read/ received.

So, what is the setup and what have I done already.

To start, I'm using a Raymarine SeaTalk backbone and connect it via a RM spur cable (Seatalk to m12 female). This cable normally connects a digital yacht AIT5000 m12 male. The setup sends the AIS and position data which are received by an I70 display. So I know my Raymarine setup is working ( has been for a while and just tested it and still works)

I wanted to install a simple solution to relay wind/ speed and location data to a screen inside the boat. After reading great reviews on BBN I decided to go this route running a PI-5. To connect I figured the bbn-m5-s3-n2k-usb was the way.

So, I ordered all the parts and constructed the lot and, according to the default spec, flashed the M5AtomS3 Lite. The RGB "green" turned "blue flashing" with a, say 0,5-ish second interval. All good I think.

After connecting it the Raymarine Seatalk backbone with the spur cable and via a USB-2 (black) port on my PI 5 I noticed two things. First, the blue flashing did not change. Second, I saw no data in Signal K. Testing for a signal on my USB port by using screen /dev/ttyACM0 115200 (I checked the port, that is correct) also showed absolutely nothing.

After testing and trying my way (with the help of an LLM) I first thought, maybe it needs a common ground as I was powering the PI via an inverter charger that is isolated. Adding the ground made no different. Then I figured, the order of the pins is different as I "just" bought the M12 pigtails via Alixpress.

So, than it might not be wired up correctly. My trusted multi meter gave 10+ V on H + G and -2,5V on L + G. Not good.
Searching online resulted in the openmarine.net page showing the order of the pins indeed is different -> exiting the spur.

So instead of, White on H, Blue on L and Black on G I think the right order should be mapping Blue on H and Grey on L with Black on G.
Rewiring and remeasuring at the input of the CAN I know see values that correspond to what is expected. Up to 2,5V on H and 1,5 -ish on L with G and about 2,5 between H and L (this is by heart so it might be a tad higher or lower.

After reconnecting the lot, keeping fingers crossed, I found the RGB consistently blinking blue with about 0,5sec interval. Again: screen /dev/ttyACM0 115200 give absolutely nothing.

Now, I'm super doubting and see the following options:

1. The setup has more intrinsic differences so the provided software bbn-flash-m5-s3-n2k-usb.sh does not work.
2. I fried the CAN bus with the 10+V (although my LLM informed it should be protected from -40 to +40 )
3. Wiring still not correct.

I can imagine number one is the most likely culprit but I'm not tech savvy enough to find/ figure out what then is different.

Now I understand this is my issue, it's rather specific for people with Raymarine and thus therefore it's not so relevant but I feel I'm the first that asks but not the first that wonders. As the Raymarine wind and depth sounder set with the i70 is reasonable value for money and with AIS on wifi in combination with Navionics on an old iPad makes sense having the ability to explain this (if we can make it working) would be good.

If desired I could create a YT video on it showing "how to" so therefor I do reach out. It's just to annoying not to get this up and running.

If you made it all this way, I'd love to hear if you have any suggestions. Maybe I'm overlooking something, maybe it "just doesn't work" or maybe a new CAN would solve it. Love to hear your thoughts!

[jwensas]

FYI: I solved it., faulty wire colouring in the end.
I will post an explanation later today.

[mgrouch]

Blue on m5stack header is not blue (it's white) on n2k cable.

[jwensas]

As mentioned, the colouring of my wires was "off". Don't know why but this is the final, working, setup:
H = Black
L = Grey
G = Blue

so I guess I have a faulty M12 plug.

[jwensas]

Black is not ground on your connector? That’s cruel

I have to agree with you on this. From the 100mio "good ones" I must have found the 1 that is not according to specs.

Long story short: if it does not work, also recheck the (voltage) on the wires.

The wiring diagram included in my previous post did the trick for me. (It just took a night of sleep to realize the picture shows a female plug and the wiring involves a male one so all should be "mirrored".

All in all, succes! Amazing setup. Love the BBN approach!💚

[mgrouch]

BTW you can now build BBN N2K sensors

https://github.com/bareboat-necessities/bbn-m5-s3-n2k-i2c

[jwensas]

BTW you can now build BBN N2K sensors

https://github.com/bareboat-necessities/bbn-m5-s3-n2k-i2c

As in a next step after this? Or b'cause I now have a way to relay the information to the PI as the sensor box connects to the N2K backbone?

[mgrouch]

BTW you can now build BBN N2K sensors
https://github.com/bareboat-necessities/bbn-m5-s3-n2k-i2c

As in a next step after this? Or b'cause I now have a way to relay the information to the PI as the sensor box connects to the N2K backbone?

If you want nmea 2000 sensors and if you are not ready to pay YachtDevices type of prices for them.

[jwensas]

Ah! Tnx! Definitely not ready to pay YachtDevices type of prices!

I’ll explore the sensors because this is another item on the whishlist indeed! :). Tnx!!