What is Node-RED?

Node-RED is a flow based programming tool, it allows all different kinds of devices to be visually “wired” together on screen in order to complete a task. Each node represents either a component, a function / processing action or an output. These nodes are represented on the visually as blocks that can be connected together to create a flow of data and logic.

In the above example the first node is the battery state of charge information held within the Victron Cerbo GX, the second node is a function node it has some logic written into it that says if the battery SOC is equal to or above 85% then send a command out to turn on the relay which is the third node. If the battery SOC falls below 85% it will turn this relay off and leave it off until the batteries reach 85% again.

This is a very basic example of what can be done with Node-RED but it is an incredibly powerful tool with endless possibilities.

How we use Node-RED

We have a lot of experience using Node-RED, we have built it into systems for our clients and our own system relies heavily on Node-RED. As our experience with Node-RED grows we are finding more and more opportunities to implement it within energy systems and we are constantly evolving our systems to take advantage of the endless capabilities that Node-RED has to offer.

We use Node-RED within our own system to move excess energy around the site to make sure none of our lovely renewable energy goes to waste. As our batteries get above 85% we start to switch on loads around the site to use this excess energy. For example the Victron EV chargers will automatically start charging the cars, next we switch on immersion heaters to heat the water in the houses, we then have a thermal store which we can heat up to provide additional hot water and heating for the outbuildings and we turn on the extra ovens on our electric Aga. All this functionality has been achieved using Node-RED, it allows us to easily connect the Victron equipment to other brands of relays / devices.

How to install Node-RED on your GX Device

In order to use Node-RED on your Victron GX device, you will need to install the Venus OS Large operating system on your device. This is basically the same operating system as the Venus OS with additional functionality of Node Red included.

Venus OS Large Installation Instructions

Compatible GX Devices:

  • Cerbo GX
  • Cerbo-S GX
  • Venus GX
  • Octo GX
  • MultiPlus-II GX
  • EasySolar-II GX

Incompatible GX Devices:

  • The Colour Control GX (CCGX) and CanVU GX cannot run Venus OS Large.

CPU & Memory Resources:

  • Node-RED is a resource-intensive application and its performance on GX devices depends on the complexity of flows and message handling.
  • Venus GX has the least resources, while Cerbo GX is faster with a dual-core CPU and more RAM, making it more suitable for Venus OS Large

Installation and Update Steps:

  1. Preparations:
    • Cerbo GX: No specific preparations required.
    • Venus GX: Install and boot v2.73 or a later version before installing Venus OS Large.
    • MultiPlus-II GX and EasySolar-II GX: No specific preparations required.
  2. Update to the Latest Firmware:
    • Update to v2.90 or later using the device's settings menu, go to Firmware > Online updates.
  3. Set Image Type to Venus OS Large:
    • In the settings menu, go to Firmware > Online updates > Image type and change it to "Large."
    • Check for a new version and install it.

Verify and Enable:

    • Verify that Venus OS Large was successfully installed.
    • Enable Node-RED, keeping in mind system resource limitations.

How to Update:

  • Both online and offline update methods can be used. The image type setting determines what image type is being updated. Refer to the GX manual for more details.

Accessing Node-RED:

  • After installation and enabling the features, configure them through a web browser.
  • To access the Node-RED flow editor, use https://venus.local:1881/. Replace venus.local with the IP address if necessary.

These instructions provide a guide for users of compatible GX devices to install and update Venus OS Large and access Node-RED.

Shelly Products

Please see our Shelly page for the full range of smart home / automation products we offer.

If you would like help getting started with Node-RED or have any other question regarding it’s capabilities feel free to contact us, also check out our blog posts for regular updates on our Node-RED experiments.