Hi everyone,
I wanted to share my recent experience with Zigbee2MQTT and TP-Link Deco X50 routers. It’s been a frustrating journey, and I hope this helps anyone facing similar issues.
The Setup
I’m running Zigbee2MQTT with around 110 Zigbee devices, including many routers. Unfortunately, I’ve been facing persistent connectivity problems and frequent device drops. One major issue is that my TP-Link Deco X50 routers don’t allow manual selection of Wi-Fi channels for the 2.4GHz band, which makes interference with Zigbee quite likely. My Zigbee network was operating on channel 20, which overlapped with the Deco Wi-Fi channels.
The Problem
This morning, I noticed a series of errors in my Zigbee2MQTT logs:
[10:41:36] error: zh:zstack:znp: Failed to determine if path is valid: 'Error: spawn udevadm ENOENT'
[10:41:36] error: z2m: Failed to set permit join to false (...) failed with status '(0x11: BUFFER_FULL)' (expected '(0x00: SUCCESS)')
These “BUFFER FULL” errors suggested that Zigbee2MQTT was overwhelmed, likely because of interference. My devices were constantly dropping, and I received warnings like this one:
[10:41:49] warning: z2m: Failed to ping 'Chambre Raph et Cel - luminaire - tradfri led light' (...) failed with status '(0x11: BUFFER_FULL)' (expected '(0x00: SUCCESS)')
The Solution: Wi-Fi Channel Optimization
Using the TP-Link Deco app, I tried the “optimize network” feature. It switched my Wi-Fi 2.4GHz channel from 9 to 2. After restarting Zigbee2MQTT, I noticed more of my devices coming back online, and the “BUFFER FULL” errors disappeared. This confirmed that channel overlap was the root cause of the problem.
Moving Zigbee2MQTT to Channel 25
I decided to change my Zigbee network from channel 20 to channel 25 to avoid future overlap with Wi-Fi. Now, my Zigbee operates on a frequency that’s well outside the range of my 2.4GHz Wi-Fi network, which is on channel 2. While I hope this improves stability over time, I can’t help but feel a bit anxious about whether it will hold.
My Disappointment with TP-Link Deco X50
To be honest, I’m relatively disappointed with the TP-Link Deco X50 routers. They are quite expensive, but the inability to manually choose and lock Wi-Fi channels is frustrating. This lack of control is causing issues with my Zigbee network, and if you’re running a setup similar to mine, I’d recommend looking for routers that give you more control over channel selection to avoid interference headaches.
Key Takeaways
For anyone running Zigbee:
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Watch out for channel overlap between Zigbee and Wi-Fi. If your router automatically selects channels, this can lead to interference and connectivity issues.
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Avoid routers that don’t allow manual channel selection, like the TP-Link Deco X50. Not being able to lock your channels might result in network instability, especially with a large Zigbee setup.
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Consider using Zigbee channel 25, as it avoids most 2.4GHz Wi-Fi interference.
I hope this helps! If anyone has suggestions or is experiencing the same issues, feel free to share. And if someone knows about better solutions (like, a hacked FW of the Deco allowing for fix the wifi channels??? ;)) let me know!