How to use a large number (9) of Bluetooth sensors with the Cerbo GX?

DIY
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1

Hi everyone,

I have a Victron Cerbo GX and I’m trying to use 9 Bluetooth sensors in total. Specifically:

  • 4 Mopeka Universal sensors for my fresh water, grey water, and two propane tanks
  • 5 RuuviTag sensors to monitor temperature in the fridge, freezer, booster area, living room, and garage

I’ve added two external Bluetooth USB dongles (both connected via USB extension cables to improve reception), and I’ve also tried disabling the internal Bluetooth of the Cerbo. However, it seems there’s no way to assign specific sensors to specific Bluetooth interfaces — for example, linking all Mopeka sensors to one dongle and the Ruuvi sensors to another.

So far, I’m experiencing issues handling all 9 devices. The Bluetooth stack seems to struggle, as the sensors frequently disconnect and reconnect. It looks like the system is constantly restarting the Bluetooth service, which affects stability.

Is there currently any way to manage this more reliably?

Does Victron have any plans to allow sensor-to-dongle assignment or improve support for multiple Bluetooth devices?

Or am I simply pushing the Cerbo beyond its intended capabilities?

Thanks in advance for your help and insights!

2

Have you tried setting Bluetooth to permanent scanning, this helped with some disconnections.

3

Yes, I’ve tried both modes — with permanent scanning enabled and disabled — and unfortunately I still experience the same issues. The sensors keep disconnecting and reconnecting constantly, especially when using all 9 devices.

It really feels like the system is overwhelmed by the number of Bluetooth connections. I’d really appreciate if someone from Victron could clarify whether this is a known limitation or if there’s any way to improve the stability.

Thanks again for your help!

4

My approach is very convoluted and I wouldn’t recommend it unless you are really stuck. In summary, my Mopeka sensors are outside Bluetooth range so I use WiFi to get their data to Victron. So I use a Mopeka bridge to send data to their cloud, use their phone app to read the data on my phone, use other apps to send the data to my server, get the data to Node Red and install Victron virtual tank sensors to use that data. So I can monitor the sensors via VRM anywhere in the world. There is possibly a simpler method but it works for me. Let me know if you need more details.

5

Would any Victron staff or experienced user be able to comment on this? I’d really appreciate any guidance.
Thanks!

6

Hi

I ​s​ee that you also have multiple Bluetooth devices in your setup. I currently have 18 Ruuvi Tags connected to one of my systems, and they have all been working perfectly without any issues.

I’m also using one of the USB Bluetooth adapters mentioned in this thread below on a 2m USB extension cable, and it’s working well for me:

(Known Good USB Bluetooth adapters? - #8 by nesswill)

While I am running the latest beta software (and ok on formal released software too), I haven’t encountered any problems with my Bluetooth devices so far. Could you let me know if your Cerbo GX is a MK1 or 2? I’m not sure if it makes a difference, but if we are running the same hardware and software, we should see similar results.

E​DIT

Just a quick note regarding the sensor’s radio signal. Please keep in mind that obstructions such as brick walls or other dense materials could potentially interfere with the signal transmission to and from the sensor.

Additionally, other devices transmitting on similar frequencies might also cause interference.
Best regards,

Dave

7

“Hi, my Cerbo is a MK1 version. Everything is installed in a motorhome, so the walls are very thin and made of wood.”

8

Hi, OK I have a MK2, did you see this from Guy? Not sure if it makes any real difference to the USB ports MK1 v MK2.
Cerbo GX MK2 - what are the differences? - Q&A and troubleshooting - Victron Community

9

I have also run many Ruuvi sensors trying to find the limit. I think I got to 20 before I decided that was enough, and didn’t have any issues (except in keeping them all organised).

I haven’t compounded that with Mopeka, perhaps that is a complication.

I would first look at trying different Bluetooth USB interfaces. I found them very cheap, so it’s easy enough to experiment.

I don’t think it’s a limitation of the GX device.

I would also be careful of the USB extension cables, they can also cause issues and for the sake of troubleshooting would try different brands of those as well.

1 Like
10

Yep, I’ve swapped in a bunch of different Bluetooth dongles and cables, tried continuous scan both on and off, and it’s always the same—devices keep popping in and out. Did you run those 20-Ruuvi tests on a Cerbo GX MK2?