Communication disturbed with RaspberryMatic add-on, RF-USB-STICK and ODROID-N2+

Hardware
1

Dear all,

I run HomeAssistant OS on an ODROID-N2+ and I recently decided to switch from using a HmIP-WLAN-HAP access point and the Homematic IP cloud integration to using a RF-USB-STICK, the RaspberryMatic Add-on and the Homematic IP local integration. The migration was, more or less, surprisingly painless :slight_smile:. That said, I am having lots of problems with broken communication with my various Homematic IP actuators.

The communication problems occur, apparently, at random. I can’t pinpoint a specific factor that could be causing it: neither Carrier Sense nor Duty cycle ever exceeds 5%. The RF-USB-STICK is connected to one of the USB 3.0 ports of the ODROID N2+ with a USB 2.0 cable and sits about 1 m away from it. To make, potentially, matters worse, a second ODROID N2+ with active USB 3.0 ports lives next to the one running HomeAssistant. Interestingly, I also have a SkyConnect dongle and it never shows any connectivity issues.

I have read many, MANY, posts on German fori about similar issues, but I am still very much baffled. When I used the HmIP-WLAN-HAP access point I never had any connectivity issues. I would think that any interference should equally affect both the HmIP-WLAN-HAP and the RF-USB-STICK, shouldn’t it?

To make things even weirder, it is clear that the communication with my various HmIP devices is actually lost several hours before the ‘Communication disturbed’ messages appear in the RasberryMatic add-on. In addition, although usually the RasberryMatic add-on says that communication is disturbed for only 2-3 devices, communication is lost with all actuators.

The only way to solve the issue is to reboot the ODROID-N2+ =(-> restart the RF-USB-STICK), which is really not ideal. Restarting HomeAssistant, or the RasberryMatic add-on, is inconsequential. This could suggest that the problem comes from a buggy RF-USB-STICK firmware that crashes and shows up a disturbed communication. If not, the RasberryMatic add-on should be able to reconnect to the various HmIP devices, after the interference is gone, shouldn’t it?

Any help is very much welcome. Thank you!

Nicola

2

I struggled with a similar problem a few months ago. One thing I discovered is that RaspberryMatic only updates Carrier Sense and Duty Cycle figures every 60 seconds or so, I think.
Have a look at these entities in the HomeMatic IP (Local) integration to see a much more detailed view. This helped me find a location for the dongle that minimised the intermittently high Carrier Sense values (up to 60%) I was seeing.
In my case I think it was caused by it’s proximity to a number of Z-Wave dimmers.

3

Thanks for the suggestions! I do follow Carrier Sense and Duty Cycle through the HomeMatic IP (Local) integration

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In the image above, I marked the points at which it is clear that something goes wrong with communication/hardware/Raspberrymatic add-on, and Carrier Sense and Duty Cycle get stuck at some value. I don’t see any consistent major spike in either metric before the start of the interference. Also, you can see that Service Messages, usually about disturbed communication, appear gradually several hours after the start of the interference.

Perhaps a basic question: is your Homematic receiver plugged in a USB 2.0 or 3.0 port? Some people claim it can make a difference.

4

From what I know, Carrier Sense levels of 5% are not a problem. I was getting 60% and more. Check the signal strength (RSSI) values under Settings - Devices in RaspberryMatic in case the reception is poor.
I changed to an RPI-RF-MOD installed on an HB-RF-ETH board with an external antenna. This made it easier to just move the unit around the house to try various locations. Each time I moved it, I had to leave it for a few days as the problem was very intermittent.
USB3 is usually considered to create more interference than USB2 so I would use that and try to keep it as far from the USB3 devices as possible.
The usual advice is to take the batteries out of each device until you find the one that is causing interference. That did not work for me as that wasn’t the problem. When I moved the HB-RF-ETH to various locations around the house, I was able to find a few locations that worked reliably.

5

A quick update, after moving the [RF-USB-STICK VERY far away from the only active USB3 I have at home, the connection seems to be stable, so far at least.