Sonoff zigbee temperature sensor and Conbee II

Support
1

I picked up a couple of these in the sale last week, and am now trying to get them to talk to my Home Assistant set-up via Zigbee 3.0 using my Conbee II.

Unfortunately Phoscon can’t see them at all, and whilst Deconz can see them as unknown devices, it can’t do anything with them.

Has anyone ever managed to use these in such a set-up, or is it strictly required to use the Sonoff bridge? There’s a web page on the Sonoff site which seems to indicate the two should be compatible, but searching the web doesn’t give any success stories for Conbee II and I fear the sensors may have to go back to Sheffield…

2

With the disclaimer that I’m an enthusiastic Home Assistant meddler, rather than any sort of expert - I don’t think you need to be using a Sonoff adaptor, but you do need device support in whatever Zigbee gateway you’re using. I’ve not had anything to do with Phoscon or Deconz but a quick Google seems to suggest their device support is rather more limited than the big two - Zigbee2MQTT and ZHA?

I’m using Zigbee2MQTT at home and ZHA at Pirate HQ, and these sensors are working for me with both the Home Assistant and Sonoff flavoured adapters.

3

I’ve got several other Zigbee devices meshed to the Conbee II and HA.

I don’t want to go to ZHA as that will definitely screw things up with everything else, and I’d wonder if Zigbee2MQTT would do the same (as I have a lot of stuff communicating via MQTT as well).

If I get chance tonight I’ll give Zigbee2MQTT a try, but I’m off on a business trip tomorrow for a couple of weeks, so the timing isn’t good!

The other reason I’m wondering is the “official” way to connect them is via their app and a QR code on the device. But that gets part way through and then says about connecting a gateway bridge, so they are clearly pushing their own product.

As for compatibility, I was going by this page on their own store which seems to imply it is (unless I’m misinterpreting it).

4

And can’t get Zigbee2MQTT to work. Presumably it’s conflicting with the existing set-up…

[2025-12-05 18:10:12] error: 	z2m: Error while starting zigbee-herdsman
[2025-12-05 18:10:12] error: 	z2m: Failed to start zigbee-herdsman
[2025-12-05 18:10:12] error: 	z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
[2025-12-05 18:10:12] error: 	z2m: Exiting...
[2025-12-05 18:10:13] error: 	z2m: Error: failed to start adapter connection to firmware
    at Timeout.<anonymous> (/app/node_modules/.pnpm/zigbee-herdsman@7.0.1/node_modules/zigbee-herdsman/src/adapter/deconz/adapter/deconzAdapter.ts:117:28)
    at listOnTimeout (node:internal/timers:588:17)
    at processTimers (node:internal/timers:523:7)

Tried disabling deconz (with restart) and it doesn’t help.

I think I’m at the point of giving up on these things. The suggested web page doesn’t give much hint, and nor does a web search for the error (although I’m not super-techie on such things either).

I emailed support last night about it and had a receipt confirmation, but nothing else received as of yet by way of reply (except here).

5

I’ve got one of these working with zigbee2mqtt and both a Sonoff dongle and the Home Assistant ZBT-1 with some Python code.

[2025-12-05 18:10:12] error: z2m: Error while starting zigbee-herdsman

If I remember right, that is often a problem with the configuration.yaml in zigbee2mqtt, did you set the adapter to deconz there?

6

Yup, I did indeed. The ConbeeII is picked up by the onboarding screen (with the MQTT server settings done in the addon configuration beforehand - it’s on the same Pi as HA via the HA addon).

Configuration.yaml

version: 4
mqtt:
  base_topic: zigbee2mqtt
  server: mqtt://192.168.0.211
  user: <redacted>
  password: <redacted>
serial:
  port: /dev/ttyACM0
  adapter: deconz
  baudrate: 115200
  rtscts: true
advanced:
  log_level: info
  channel: 25
  network_key:
    - 176
    - 149
    - 146
    - 201
    - 212
    - 212
    - 164
    - 171
    - 28
    - 156
    - 214
    - 30
    - 215
    - 100
    - 50
    - 17
  pan_id: 32210
  ext_pan_id:
    - 21
    - 133
    - 142
    - 31
    - 134
    - 156
    - 19
    - 194
frontend:
  enabled: true
  port: 8099
homeassistant:
  enabled: true
onboarding: true

Log:

[21:47:57] INFO: Preparing to start...
[21:47:57] INFO: Socat enabled
[21:47:57] INFO: Starting socat
Socat startup parameters:
Options:     -d -d
Master:      pty,raw,echo=0,link=/tmp/ttyZ2M,mode=777
Slave:       tcp-listen:8485,keepalive,nodelay,reuseaddr,keepidle=1,keepintvl=1,keepcnt=5
[21:47:57] INFO: Starting socat process ...
2025/12/05 21:47:57 socat[46] N PTY is /dev/pts/1
2025/12/05 21:47:57 socat[46] N listening on AF=2 0.0.0.0:8485
[21:47:58] INFO: Starting Zigbee2MQTT...
Starting Zigbee2MQTT without watchdog.
Onboarding page is available at http://0.0.0.0:8099/
[2025-12-05 21:48:21] info: 	z2m: Logging to console, file (filename: log.log)
[2025-12-05 21:48:22] info: 	z2m: Starting Zigbee2MQTT version 2.7.0 (commit #unknown)
[2025-12-05 21:48:22] info: 	z2m: Starting zigbee-herdsman (7.0.1)
[2025-12-05 21:48:22] info: 	zh:adapter:discovery: Matched adapter: {"path":"/dev/ttyACM0","manufacturer":"dresden elektronik ingenieurtechnik GmbH","serialNumber":"DE2226981","pnpId":"usb-dresden_elektronik_ingenieurtechnik_GmbH_ConBee_II_DE2226981-if00","vendorId":"1cf1","productId":"0030"} => deconz: 4
[2025-12-05 21:48:42] error: 	z2m: Error while starting zigbee-herdsman
[2025-12-05 21:48:42] error: 	z2m: Failed to start zigbee-herdsman
[2025-12-05 21:48:42] error: 	z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
[2025-12-05 21:48:42] error: 	z2m: Exiting...
[2025-12-05 21:48:42] error: 	z2m: Error: failed to start adapter connection to firmware
    at Timeout.<anonymous> (/app/node_modules/.pnpm/zigbee-herdsman@7.0.1/node_modules/zigbee-herdsman/src/adapter/deconz/adapter/deconzAdapter.ts:117:28)
    at listOnTimeout (node:internal/timers:588:17)
    at processTimers (node:internal/timers:523:7)
7

With debug logging enabled, it becomes a bit clearer perhaps.

Looks like something is already communicating there. May be the deconz addon that I’ve generally been using until now, but I tried to disable that earlier and it still had the same issue.

[22:06:50] INFO: Starting Zigbee2MQTT...
Starting Zigbee2MQTT without watchdog.
Onboarding page is available at http://0.0.0.0:8099/
[2025-12-05 22:07:05] debug: 	z2m: Removing old log directory '/config/zigbee2mqtt/log/2025-12-05.18-03-29'
[2025-12-05 22:07:05] info: 	z2m: Logging to console, file (filename: log.log)
[2025-12-05 22:07:05] debug: 	z2m: Loaded state from file /config/zigbee2mqtt/state.json
[2025-12-05 22:07:05] info: 	z2m: Starting Zigbee2MQTT version 2.7.0 (commit #unknown)
[2025-12-05 22:07:05] info: 	z2m: Starting zigbee-herdsman (7.0.1)
[2025-12-05 22:07:05] debug: 	z2m: Using zigbee-herdsman with settings: '"{\"network\":{\"panID\":32210,\"extendedPanID\":[21,133,142,31,134,156,19,194],\"channelList\":[25],\"networkKey\":\"HIDDEN\"},\"databasePath\":\"/config/zigbee2mqtt/database.db\",\"databaseBackupPath\":\"/config/zigbee2mqtt/database.db.backup\",\"backupPath\":\"/config/zigbee2mqtt/coordinator_backup.json\",\"serialPort\":{\"baudRate\":115200,\"rtscts\":true,\"path\":\"/dev/ttyACM0\",\"adapter\":\"deconz\"},\"adapter\":{\"disableLED\":false}}"'
[2025-12-05 22:07:06] debug: 	zh:adapter:discovery: Connected devices: [{"path":"/dev/ttyACM0","manufacturer":"dresden elektronik ingenieurtechnik GmbH","serialNumber":"DE2226981","pnpId":"usb-dresden_elektronik_ingenieurtechnik_GmbH_ConBee_II_DE2226981-if00","vendorId":"1cf1","productId":"0030"}]
[2025-12-05 22:07:06] info: 	zh:adapter:discovery: Matched adapter: {"path":"/dev/ttyACM0","manufacturer":"dresden elektronik ingenieurtechnik GmbH","serialNumber":"DE2226981","pnpId":"usb-dresden_elektronik_ingenieurtechnik_GmbH_ConBee_II_DE2226981-if00","vendorId":"1cf1","productId":"0030"} => deconz: 4
[2025-12-05 22:07:06] debug: 	zh:controller: Starting with options '{"network":{"networkKeyDistribute":false,"networkKey":"HIDDEN","panID":32210,"extendedPanID":[21,133,142,31,134,156,19,194],"channelList":[25]},"serialPort":{"baudRate":115200,"rtscts":true,"path":"/dev/ttyACM0","adapter":"deconz"},"adapter":{"disableLED":false},"databasePath":"/config/zigbee2mqtt/database.db","databaseBackupPath":"/config/zigbee2mqtt/database.db.backup","backupPath":"/config/zigbee2mqtt/coordinator_backup.json"}'
[2025-12-05 22:07:06] debug: 	zh:deconz:driver: Opening serial port: /dev/ttyACM0
[2025-12-05 22:07:06] debug: 	zh:deconz:driver: Error: Error while opening serialport 'Error: Error: Resource busy, cannot open /dev/ttyACM0'
[2025-12-05 22:07:11] debug: 	zh:deconz:driver: Opening serial port: /dev/ttyACM0
[2025-12-05 22:07:11] debug: 	zh:deconz:driver: Error: Error while opening serialport 'Error: Error: Resource busy, cannot open /dev/ttyACM0'
[2025-12-05 22:07:16] debug: 	zh:deconz:driver: Opening serial port: /dev/ttyACM0
[2025-12-05 22:07:16] debug: 	zh:deconz:driver: Error: Error while opening serialport 'Error: Error: Resource busy, cannot open /dev/ttyACM0'
[2025-12-05 22:07:21] debug: 	zh:deconz:driver: Opening serial port: /dev/ttyACM0
[2025-12-05 22:07:21] debug: 	zh:deconz:driver: Error: Error while opening serialport 'Error: Error: Resource busy, cannot open /dev/ttyACM0'
[2025-12-05 22:07:26] error: 	z2m: Error while starting zigbee-herdsman
[2025-12-05 22:07:26] error: 	z2m: Failed to start zigbee-herdsman
[2025-12-05 22:07:26] error: 	z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
[2025-12-05 22:07:26] error: 	z2m: Exiting...
[2025-12-05 22:07:26] error: 	z2m: Error: failed to start adapter connection to firmware
    at Timeout.<anonymous> (/app/node_modules/.pnpm/zigbee-herdsman@7.0.1/node_modules/zigbee-herdsman/src/adapter/deconz/adapter/deconzAdapter.ts:117:28)
    at listOnTimeout (node:internal/timers:588:17)
    at processTimers (node:internal/timers:523:7)
8

I assume you’ve tried unplugging / replugging the adaptor and restarting HA after removing the old add-on? (and checking that ZHA hasn’t auto-detected the adapter and decided to get involved too?)

9

Yup. They just won’t play nicely.

I think I’d like to return them both - I emailed support last Friday and got a read receipt but nothing beyond that yet. Can you see what’s going on there as I didn’t log in when I made the request so not sure it worked right…

10

Sorry to hear that - looks like there was a big rewrite of the deconz driver earlier this year, so I wonder if that might be causing some issues?

I dropped you a reply to your ticket this morning - let me know if I need to resend it :)

11

Thanks @hel . Got your mail.

I’m on a business trip until next week so testing is slow, but as I have several other devices in place, it would be quite some work to switch to z2m and redo all of those in HA.

Especially given the age of the Conbee 2 it may be better at a future point to update it to a different antenna solution.

For now I think it’s going to be easier to return the sensors, so if you can let me know how to go about that I’ll make arrangements.

12

Yeah, when I was Googling around I found quite a few posts from folks having trouble with Conbee 2, so I agree that switching to a different Zigbee adapter might be the easiest way of improving compatibility.

Dropped you another reply :)