sonoff Dongle-M as OTBR? | Home Assistant | Page 1

stiff phoenix Jan 28, 2026, 3:03 PM

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Hello,
My HA setup is as follows:

X86/64 mini PC
Sonoff Dongle-P connected via USB
Sonoff Dongle Max connected via WiFi
HA core v2026.1.3/supervisor v2026.01.1/OS v17.0

My intention is to leave the management of the Zigbee devices to the Dongle-P/ZHA and delegate the management of the matter/thread peripherals to the Dongle Max.

Reading all the links I found, the Dongle-Max configuration connected via WiFi with "EFR32MG24 Operation Mode" set to "Thread RCP Mode" should be supported.

All attempts to add OTBR to HA, however, fail, and I can't find a solution.
As soon as I try to install the OTBR device on HA, I'm prompted to "Provide URL for the OpenThread Border Router's REST API." Unlike all the documentation I've read, I have no way to configure any 'dummy' devices so I can manually edit the yaml later. As soon as I try to install the add-on, I'm prompted for the URL and can't continue.

I tried entering:
socket://Dongle-M.local:6638
tcp://Dongle-M.local:6638
http://Dongle-M.local:6638
dongle-M.local

I've also used the IP address to avoid DNS resolution issues, but nothing has worked. The error always returns "Unable to connect!"

I've checked and Dongle-M's port 6638 is reachable on my home network, and I've rechecked the dongle configuration countless times.

I checked all the HA logs and found no trace of any particular errors.

Has anyone ever managed to complete the OTBR configuration?

Thanks

cobalt cedar Jan 28, 2026, 3:35 PM

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I'd recommend doing it the other way around. Using thread with a network-connected radio is not recommended, especially over wifi, due to the radio communication protocol being very timing sensitive

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you'll have a better time and it'll be easier to set up if you use the usb radio for thread and network radio for zigbee

stiff phoenix Jan 28, 2026, 3:44 PM

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thnak you for your suggestion. i will check if dongle-P is thread/matter capable.

cobalt cedar Jan 28, 2026, 4:12 PM

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oh, right, that's the TI CC2652P chipset one. It looks like a thread rcp firmware is available for it, but I haven't seen as many people using it as I've seen using the silicon labs chipset.

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sonoff does not appear to provide a first party thread rcp firmware for the ZBDongle-P

cobalt cedar Jan 28, 2026, 4:51 PM

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Regarding the error you're seeing - you're adding the OTBR integration (what HA uses to talk to an external OTBR to do things like retrieve network credentials or change channel), but the Dongle-M is not itself a thread border router, it's just a thread radio.

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You need to add the OTBR add-on ("OpenThread Border Router") which is what talks to the thread radio and actually implements the thread border router

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(when you install the add-on, home assistant will automatically configure the integration for you)

bleak kestrel Jan 28, 2026, 9:29 PM

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Just to chime in here, I have both P and E Dongle. The P Dongle doesn't have official OpenThread support. There is unsupported custom firmware that I never got to work it only kept being detected by ZHA. The OpenThread Router never booted for me when assigned.

That being said I bought the E and Flashed it with the OpenThread 2.4.4 using the SONOFF Dongle Flasher, it takes about a minute. In my case Open Thread only boots when I disabled Hardware Flow Control.

My only issue is that I haven't been able to get the Companion App to work and get the Credentials Properly with iPhone or Android. I had to use a Bluetooth Adapter and Commission Node via the Matter Server directly. Debating on getting the ZBT-2 for that reason.

stiff phoenix Jan 28, 2026, 9:36 PM

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thanx @bleak kestrel i have a second HA installation in a second home which is using Dongle-E, so i can think about a switch with dongle-P. @cobalt cedar really precious point. will work on suggestions from both of you starting from now. I will keep you informed about the end of this setup, just to give a help to anyone else with same setup and the same need

stiff phoenix Jan 28, 2026, 9:54 PM

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quick feedback: just added a brand new ikea temp and humidity sensor using dongle-M. Now i'll work for moving to dongle-E OTBR

cobalt cedar Jan 28, 2026, 9:55 PM

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companion app issues are completely unrelated to the specific radio dongle being used; getting a zbt-2 wouldn't do anything to help or hurt that.

#sonoff Dongle-M as OTBR?