OpenMarine

Hi.

a. Can I remove my Raymarie E80 plotter and connect the Seatalk1 cables from there directly to the MacArthur HAT without any additional hardware? The plotter does not have any magic routing hardware for the Seatalk1 (I don't know how it works)?

b. Probably the E80 is supplying the power to the Seatalk1 network, so I guess I will just add +12V to the Seatalk1 network, conect the Data wires that was in the E80 in paralell to the HAT and the ground wires to ground - (minus)? I will follow the MacArthur HAT documentation.

My Seatalk1 setup is currently:
1. E80 plotter + radar
2. ST60+ Tridata display with Airmar sensor (speed and depth) 
3. GPS RS125
4. Magnetic compass
5. ST4000+ Autopilot with the Fluxgate Compass (4.) and control display panel.
6. CTRX AIS
7. VHF with DCS

I want to keep 4. 5. 6. 7. (.3 if I can't multiplex GPS from SignalK to Seatalk1, or maybe as backup?)
I'm replacing the 1. with OpenPlotter with MacArthur Hat and Navionics on my iPad, the 2. with the I70S Depth, SPEED AND WIND PACK (SKU T70216)  

I've been watching Boating With The Bailys (great inspiration!) and https://www.youtube.com/watch?v=P4azdcAPwbg specificly, but I want to get rid of the E80.
B
BB

a. Yes you can. Just follow the manual: https://macarthur-hat-documentation.read...atalk.html

b. The E80 is NOT powering the seatalk1 network. The seatalk1 network must be powered from the battery. The E80 must be powered from the battery and also be connected to the +12V wire of the seatalk1 network. Same for the MacArthur hat, it must be powered from the battery and it needs also +12V SW:





Please note that the radar uses its own data cable to communicate with the E80. Seatalk1 does not contain the radar data and the radar cannot be connected to the MacArthur HAT.

(2025-01-15, 09:52 PM)Sailoog Wrote: [ -> ]a. Yes you can. Just follow the manual: https://macarthur-hat-documentation.read...atalk.html

b. The E80 is NOT powering the seatalk1 network. The seatalk1 network must be powered from the battery. The E80 must be powered from the battery and also be connected to the +12V wire of the seatalk1 network. Same for the MacArthur hat, it must be powered from the battery and it needs also +12V SW:





Please note that the radar uses its own data cable to communicate with the E80. Seatalk1 does not contain the radar data and the radar cannot be connected to the MacArthur HAT.

Thank you.

Regarding the power, I want to be able to independently turn on and off the RPI and Seatalk1 network. I do currently on my bench at home have the RPI with the power module to the HAT and have the SW to12v  power via a separate fused switch and configured to shut down the RPI gracefully when the switch is toggled off, works great.
So my thinking is to have separate power with a separate fused switch to the Seatalk1 network. The autopilot already have a separate fused switch.

Any inputs are gratefully received.

Hi, Its likely that the power for the Seatalk 1 network is coming from the Autopilot rather than the E80. That might have its own power supply but network power on mine was via the pilot. I ran a very similar setup and just connected the HAT to the next seatalk port and then I could see the whole lot. The E80/C80 is only really a display and possibly where your radar connects.

(2025-01-16, 05:41 AM)GuteLappen Wrote: [ -> ]Regarding the power, I want to be able to independently turn on and off the RPI and Seatalk1 network. I do currently on my bench at home have the RPI with the power module to the HAT and have the SW to12v  power via a separate fused switch and configured to shut down the RPI gracefully when the switch is toggled off, works great.
So my thinking is to have separate power with a separate fused switch to the Seatalk1 network. The autopilot already have a separate fused switch.

Any inputs are gratefully received.

Hi GuteLappen,

I'm facing the same challenge here. I don't want to leave my Seatalk instrumentation powered ON in order to have the Raspberry Pi running, as I run stuff in the Pi 24/7, e.g sensors readings.

Did you get to any resolution with this?

I understand that for the MacArthur Seatalk1 input to work, it must receive 12v (red) and Data (yellow) from the Seatalk bus on 12V SW and DATA in the HAT.
If the above is correct, could I connect my separate 12V switch from the battery to the HAT, along with the 12V from the Seatalk bus, to the 12V SW interface of the HAT?

My setup: Rpi5 + Openplotter 4 + MacArthur HAT 1.2 + Power module

Any help greatly appreciated! Thanks

I think, and would need @Sailoog or others involved in the board design to confirm, but as long as SeaTalk and the Pi are powered from the same positive supply, i.e the house battery bank, you could just connect the yellow data wire and power your pi how you see fit. It wont receive any Setalk data without power to your Seatalk kit, but your pi would remain powered.

I think I tried this, but mine is setup to turn the Pi off and on with my other instruments powered. The ST series use so little power, I just leave it on all the time so I can see wind/depth data in my dashboards.

That's correct, Seatalk will work fine if the 12V SW is powered from the same 12V source as the Pi rather than Seatalk. You can safely power down your Seatalk devices while the Pi keeps running.

Thank you @Boatingbaileys, @Adrian

I finally got time to tinker again with my installation and got it working i.e. using a separate switch on 12V SW directly connected to the same battery that powers the cockpit instrumentation -- and only connecting the DATA cable at the end of the Seatalk bus back to the HAT.

Why did this not work from the start? tl;dr --> cable cross-section powering the cockpit too small

I'll leave here my troubleshooting process in case it helps any future reader:
Once I realized that the SeaTalk bus’s DATA terminal is referenced to the 12V supply rather than ground, I compared the voltage powering the HAT with the voltage at the autopilot head unit in the cockpit. The difference was more than 1.5V, which meant the DATA terminal at the end of the bus was also off by that amount. The small cable cross-section was causing a significant voltage drop. Switching to a larger-gauge cable solved the problem immediately.

Good bit of troubleshooting - glad it's working how you want it to.