I have a project I'm working through on my sailboat. I'm attempting to interface a Raspberry Pi running Victron OS (SignalK and Node Red version) and a BMS that outputs 3 (0-5vdc) analog signals one of which being State of Charge for the battery bank (16 CALB lifepo4 cells, 48V).
My objective is to be able to send SOC data (and maybe other analog signal data) to Victron OS in such a way that it shows up on VRM portal, if possible (monitor data remotely).
If this doesn't work out, my fallback plan is to try this with Node Red with SignalK -- but I'd really like to do this all through VRM for a clean interface. (the sailboat gauges will display some of this data via SignalK anyway later -- a project for another time)
My Options and obstacles are:
1. Modbust TCP via Arduino w/ Ethernet Shield. Have gotten Arduino to read analog values from BMS. Used a Modbus Utility to connect and pull register data from Victron Pi. Limitation it seems is that data registers in com.victronenergy.system are not writable per the excel spreadsheet notes. My understanding is that com.victronenergy.system is where the GUI displays data from (and also VRM uses this?). And the com.victronenergy.vebus VE.Bus state of charge although writable, will not show up in VRM portal (https://www.victronenergy.com/live/vrm_portal:faq).
Haven't tried these yet:
2. Ve.Can via Arduino w/ CANBUS shield.(https://community.victronenergy.com/answers/5364/view.html)
Looks like there is CAN bus registers reference doc available from Victron that I can use.
Problem: Victron Pi does not have on-board CAN bus, would need to research a compatible CANBUS shield that would work with Victron OS w/o too much fuss.
3. Ve.Direct via Arduino w/ onboard RS232 communication. Maybe sending something like MV700 HEX messages over serial? (MV-7xx-HEX-Protocol-public.pdf)
4. Analog signal directly to Victron Pi
Problem: No analog inputs on RpI, would have to add an ADC adapter board for RpI (https://community.victronenergy.com/questions/40928/how-do-i-access-the-unused-analogue-input-on-the-r.html). Will these even show up in VRM portal?
My final problem is that I'm not good at coding, (mechanical engineer by trade, but I enjoy tinkering :) and this has been an interesting problem so far and seems like a fun dive into the software/microcontroller world.)
What would be your recommendation on how to proceed or perhaps any other suggestions that you may have of what I can try to get my interface worked out?
Thank you and best regards!