feature-request venus-os cerbo-gx node-red marine

Been thinking about this one for a while with my static caravan setup.

The Cerbo GX digital inputs are genuinely useful but they feel a bit half-baked when you want proper control. Right now you're essentially limited to monitoring states — tank levels, door contacts, that sort of thing. What I'd love to see is the ability to flip one of those inputs into a momentary action mode, so a simple push-button on the wall could toggle a relay without needing a full Node-RED flow just to handle the logic.

Don't get me wrong, Node-RED on Venus OS is brilliant and I use it for most of my automation, but for something as simple as "press button → toggle relay 2 for 30 minutes" it feels like overkill. A native config option in the GX interface would be far cleaner, especially for anyone less comfortable messing about with flows.

Practical example from my van: I've got a Victron Cerbo managing everything, and I want a physical override button near the door for my water pump relay — no phone, no VRM portal, just a button. Currently I've bodged it through Node-RED but it broke after a firmware update and took me a weekend to sort.

Has anyone else raised this with Victron directly? Their community forum is the right place apparently but getting traction there can be slow.

Also curious — is anyone doing this differently? Physical relay timer modules wired in parallel, maybe? Or a separate ESP32 talking MQTT back to the Cerbo?

Would be good to hear what others have cobbled together in the meantime.

@WD40Wizard Node-RED on Venus OS is the answer here. Once you enable it via the large image, you can read those digital inputs directly from the D-Bus and build proper logic around them — debounce timers, state machines, the lot.

On my boat I've got a bilge float switch wired into a Cerbo digital input, then Node-RED handles:

• Latching the alarm state
• Writing back to a virtual switch via com.victronenergy.system
• Pushing MQTT notifications to my phone

The built-in digital input UI is basically just for display. The real flexibility lives in Node-RED or Python scripts if you prefer. Victron's community Node-RED palette is decent starting point — search node-red-contrib-victron on npm.

What specifically are you trying to trigger? Might be able to share a flow snippet.

@CaddyProject is right that Node-RED is the way forward, but worth flagging for anyone on a narrowboat (like me) — the Cerbo's digital inputs respond quickly enough for bilge pump monitoring if you wire them properly, but I found the debounce timing catches people out when they're using reed switches on hatches or whatever.

What I've actually done is run a small flow that watches the digital input state changes and cross-references them against SOC from the battery (Fogstar Drift 200Ah here) before triggering any relay logic. Keeps the MQTT chatter sensible too.

The bit that is genuinely half-baked is the VRM dashboard side — Node-RED logic doesn't surface there cleanly. You still end up screen-shotting your flows to share with anyone who needs to understand the setup.

Has anyone actually mapped out which digital inputs on the Cerbo GX can be configured as outputs via Node-RED versus which ones are genuinely input-only at the hardware level? I've been trying to work out whether I can drive a relay directly from the Cerbo on my narrowboat or whether I'd still need a separate relay module between it and whatever I'm controlling. The documentation feels quite vague on this. Also curious whether the Node-RED integration survives a Venus OS firmware update cleanly — losing a working flow mid-winter on a boat isn't something I fancy dealing with.

@GoldenTinker yes this is something I've been trying to nail down properly for my static and it's... not straightforward.

From what I've documented on my own Cerbo (firmware 3.x, large image):

• Digital inputs 1-5 — readable via MQTT/Node-RED at digital_input/X/state
• Relay outputs (the two physical relays on the Cerbo itself) — these are writable via Node-RED using the com.victronenergy.system MQTT paths

The confusion is that the digital inputs are genuinely input-only at the hardware level. You can't flip them to outputs in software, regardless of what Node-RED does. The relay contacts are separate terminals entirely.

Where I got muddled was thinking the "programmable relay" label meant the DI pins could switch. They cannot.

For actual switched outputs beyond the two onboard relays, I ended up wiring through a Victron-compatible IO expander. Worth checking your physical terminal layout before assuming any flexibility there.