Hi,
I would like to change the Boat Page to add control of a Marine AC Unit connected to Cerbo via CAN bus (adding a small GUI).
How would you proceed in this?
As both CAN Ports are used (one for NMEA and one for BMS) I would need to add a USB to CAN interface. What would be the one recommended to use?
Many Thanks for your thoughts,
C.
I’m using Cerbo GX in version VE.CAN and BMS.CAN
The new GUI is used in the latest Version v3.70~23
Consider to connect these virtually by Signal K and my plugin Signal K to Venus: https://www.npmjs.com/package/signalk-to-venus. You wont need a cable.
If have a couple of questions, assuming there is already a (primary) Cerbo GX running on a local lan:
Cheers and welcome to the forum @Krillle
@Lindi Thank you for the warm welcome. 
Is a secondary device / rPi required?
You will need a Raspberry Pi or similar device running Linux with Signal K server. Check: signalk.*org
Even though there is an option to install Venus OS large on the Cerbo, as far as I understand this is mainly to deliver data from the Cerbo. AFAIK you cant install plugins as on a Raspberry Pi.
You then want to connect your boat’s communication bus, like NMEA 200. The standard interface would be the Actisense NGT-1: actisense.*com/products/ngt-1-nmea-2000-to-pc-interface/
Once you have Signal K on your boat, you would not want to miss it’s universal communication options any more.
What OS is required on secondary device, venusOS large with Signal-K or other?
Debian Linux, wich is called raspberry Pi OS. See raspberrypi.*com/software/
Does this work Node-RED enabled on primary Cerbo GX?
It is sending data for virtual devices directly to Cerbo GX Venus OS via dbus. No Node-RED used. I made the plugin, as Node-RED felt too much overhead to me.
You need to enable D-Bus over TCP on the Cerbo GX as described in the readme: https://www.npmjs.com/package/signalk-to-venus
If you get the AC Unit connected to Signal K (assuming we are talking about air-condition, not AC power supply), you can map its controls to a virtual switch in Signal K. This switch could be switched via the Cerbo GX. Check for Signal K connection and plugins for your AC: https://www.npmjs.com/search?q=signalk-node-server-plugin
Switches are available in the new Venus OS beta. I am working on implementing these to my plugin.
This could be your solution. Adding an individual GUI for the Venus is not possible, AFAIK.
(Sorry for the disabled links. I needed to add * to the domain names, as I am allowed to only post two links for now.)
Thanks for the extended explanation. I’m a fan of Node-RED as it provides an easier learning curve to get started with something new and have yet to run into any performance issues. For a marine customer I am looking to integrate the AIS GPS data to complement the Sevcon motor data for display on the guiv2 boat page. Adding a secondary rPi plus yet another h/w interface device for just that seems to be adding a bit too much complexity for just that objective so I’ll stick to an USB GPS mouse for the time being. That said, I’m sure the topic of integration of the VenusOS with the Signal-K platform will resurface for us in the not so distant future, I’ll revisit your solution again by then. Thanks for sharing your work.