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Node Red: Relais on Smart Solar


I would like to control a heating rod in Node Red. To do this, I would need to use the relays from two Smart Solar. Everything should actually fit in my Flow, but I can't switch the relays. Do I have to make a presetting in the devices themselves, as I have to do with the Cerbo (setting: Manual)?
Or is it because the Smart Solar are currently "Off" due to the lack of solar input?
Or what could be the reason that the relays do not switch?

Greetings from the Ambergauer

Translated with (free version)

der-ambergauer asked

0 Answers

I2C relay board or GPIO

I purchased an i2c relay board (DockerPi 4 CHannel Relay) that I hoped to use with my RPI running Venus OS to control some DC circuits based on temperature, battery voltage, etc. When I bought it, I wasn't aware of the differences between controlling the relays with i2c vs the GPIO pins (still not really clear on it). I see many instructions for installing extra relays that are controlled via node red etc by mapping the GPIO pins but not really anything on an i2c controlled relay board.

Is it possible (for an average diy enthusiast) to use this board in the manner I am desiring, or should I just look for a different GPIO relay board that others have already used to make this work?


smallsolar asked
smallsolar edited ·

2 Answers

Can I add more switches to controls on the dashboard.

I would like to add some more virtual relay/switches to the controls on the dashboard. The controls is a convenient connection to ‘Venus OS Lage/node red’.

claus asked

0 Answers

Node red : Multiplus II primary relay

Dear all,

My installation consists of solar panels, Pylontech batteries, a Multiplus II, and a Solar Charger MPPT 450/100. This set is controlled by a CERBO GX. I have installed Venus Large and Node-RED.

I already control a hot water tank from a CERBO GX relay programmed with Node-RED.

I would also like to program the primary relay of the Multiplus II via Node-RED. I can do this with the Relay Assistant but cannot find it with Node-RED. Do you have an idea?


jeromed asked
Dirk-Jan Faber commented ·

3 Answers

Add Relays - Does anyone have a an ‘idiots guide' on how to add more Relays to a VenusPi set up?

I’m only semi-computer literate - everything is trial and error and cut and paste and hours of google research… If the details include what software should be used and exactly what to type then I can usually muddle my way through. But when it comes to ‘just add a few lines of code in the xxx” I’m completely lost.

I have managed to burn an image to a sd card and install Venus Pi v2.60 large image on to a raspberryPi 3.

I have 1 Victron mppt 75/15 connected successfully to it vie ve-direct usb cable.

I have successfully got node-red running (and can even see it all via VRM Portal - including node-red which is amazing).

I’m still at beginnings of how node red works but can see its potential.

So far so good

But I’d really like to add more than 1 relay so I can control multiple external devices (like pumps, irrigation valves etc) and also control them through node red.

I’ve read the comments and half guides for adding extra relays - but they are incomplete or presume you know how to do certain un-explained steps. So I'm completely lost.

So - anyone have a step by step guide to add relays ? (and I’m on a Mac so Mac instructions would be great!)

Thanks in advance for all the amazing guides so far - and for the missing bits I hope someone will write soon…

thomas-g asked
Rob Duthie commented ·

4 Answers


Modbus Register for Relay 3,4,5&6 for Raspberry pi

Where might I find the Modbus registers for the Extra relays the Raspberry pi has? I have looked in the Excel Modbus-TCP register list, but can only find Relay 1 and 2.

I used the RpiGPioSetup add-on to assign the extra relays. I can see and control the extra relays using Remote Console.

I currently have NodeRed running on external device controlling Relay 1 and 2. I am looking to control the other relays (3-6). NodeRed is also pulling data from my BMV-712 / other Victron items.

mrorange asked

0 Answers

More relay outputs with Cerbo GX

Hi All,

have a small setup in the caravan and would love to have more than 2 relay outputs controlled from the Cerbo GX. What is the most self-contained way I can do this?

On my system at home, Node Red running on the Venus GX can control my zigbee relays over MQTT, but this setup requires I have a network router and zigbee bridge running all the time. At home, this is not a problem because they are in constant use by the smart home devices anyway, but in the caravan, I'm trying to minimize how much stuff needs to be left on.

Your input is much appreciated.

Many thanks

ceriw asked
gone-sailing answered ·

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