Rich Bernhardt avatar image
Rich Bernhardt asked

Connecting NOT-supported NON-Victron RS485 irradiance sensor


I'd like to connect an RS485 irradiance sensor to a Cerbo GX where the sensor is a non-victron product and also outside the list of supported ones. Solar Radiation Sensor(RS485).docx.pdf

My question: should this not-supported RS485 sensor be appear in anywhere in Cerbo's Remote Console interface - similar to this example from the manual?1714902919466.png

This is the sensor: Solar Radiation Sensor(RS485).docx.pdf

My main goal is accessing the sensor in Node-Red...


PS: The CerboGX manual completely omits the chapter: "connecting NOT-supported NON-victron products" -

cerbo gxNode-REDModbus TCPrs485irradiance monitoring
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matt1309 avatar image
matt1309 answered ·

Not sure this will be much help but here's the code for what's adding the driver to gx device:

It's written quite differently to other drivers so harder for me to follow quickly. I also dont have an irradiance sensor.

However i think the is what you'll need to tweak most to integrate non supported sensors assuming your sensor is also modbus rtu. ie edit the modbus registers noted in the to correspond with your unit. You may also need to tweak units and factors if yours differs.

Not a complete answer sorry but hopefully enough to get you started.

These github files can be found on your gx device in the folder /opt/victronenergy/dbus-imt-si-rs485tc folder.

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Rich Bernhardt avatar image Rich Bernhardt commented ·
Hi Matt.

Many thanks for your help. Sorry for my late response, but haven't received a notification about your answer (email about relocation of my question has arrived twice).

I've never installed any packages before onto Cerbo. Could you please navigate me through the steps? I use the latest Ubuntu Linux on my laptop. Many thanks Matt

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matt1309 avatar image matt1309 Rich Bernhardt commented ·

Hi @Rich Bernhardt

(Sorry i shouldve @ you in my original response)

Sure cerbo runs, venus os (openembedded) which is linux so you'll be somewhat familiar. It doesnt have apt package manger but does have opkg for some limted tools. Or you compile new programs yourself.

To get remote access you need to enable root access and ssh in: Enabling that is explained her:

Venus OS: Root Access [Victron Energy]

Once you're in it'll be a case of customising the driver.

You might want to copy the above driver that is used for the stock irradiance sensor. Just so you dont break it (you can redownload from github if you do so not a massive deal).

Once you're in it's just like any linux system. I cant remember if nano is installed by default or if i needed to install via opkg install nano

However it might be easier using sftp or similar to write the changes on a editor on your local machine before transferring over to cerbo.

Custom drivers development section on here might also be a usseful read to understand how the drivers tend to work if you've not messed with one before:

Home · victronenergy/venus Wiki · GitHub

This one does looks older/different layout to many others but similar concepts.

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