Ezsp To Ember - I'm confused with my ethernet coordinator

[Micharius]

Hello everyone. I'm using Z2M in combination with an Eachen eWeLink ZbBridge Pro, running on Tasmota and configured as Zigbee Bridge.

From the Z2M log I got the warning: zh:ezsp: 'ezsp' driver is deprecated and will only remain to provide support for older firmware (pre 7.4.x) message.
Off course I did some research, but all information I find point out to devices as adapters and dongles, not the one I'm using.

So that leaves me with some questions...

• Do I need to switch to ember driver. I know, never change a running system but will the device stop working with future updates?

• Speaking of never change a running system - My whole configuration was run very smoothly when I set it up a couple of months ago, but I recently experienced problems when binding Ikea Tradfrik remotes to Ikea lamps - something that was never a problem before. Now I cannot bind any of my 3 Tradfri remotes to any lamp anymore, Even bindings, that worked before, generating errors such as this

error 2025-08-30 18:01:58zh:ezsp:ezsp: Frame changeSourceRouteHandler parsing error: RangeError [ERR_BUFFER_OUT_OF_BOUNDS]: Attempt to access memory outside buffer bounds
error 2025-08-30 18:01:58zh:ezsp:ezsp: Unparsed frame 0xc4. Skipped
error 2025-08-30 18:02:00z2m: Failed to bind cluster 'genOnOff' from 'TRADFRI RC Wohnzimmer' to 'IKEA Wohnzimmer' (Error: Bind 0x30fb10fffe5b46b7/1 genOnOff from '2' failed ({"address":12706,"clusterId":32801,"sequence":45} after 10000ms))
'{"brightness":254,"effect":null,"identify":null,"linkquality":156,"power_on_behavior":null,"state":"OFF","update":{"installed_version":65552,"latest_version":16842756,"progress":75.58,"remaining":6827,"state":"updating"}}'
error 2025-08-30 18:02:08zh:ezsp:ezsp: Frame changeSourceRouteHandler parsing error: RangeError [ERR_BUFFER_OUT_OF_BOUNDS]: Attempt to access memory outside buffer bounds
error 2025-08-30 18:02:08zh:ezsp:ezsp: Unparsed frame 0xc4. Skipped
error 2025-08-30 18:02:10z2m: Failed to bind cluster 'genLevelCtrl' from 'TRADFRI RC Wohnzimmer' to 'IKEA Wohnzimmer' (Error: Bind 0x30fb10fffe5b46b7/1 genLevelCtrl from '2' failed ({"address":12706,"clusterId":32801,"sequence":48} after 10000ms))
info 2025-08-30 18:02:10z2m:mqtt: MQTT publish: topic 'zigbee2mqtt/bridge/response/device/bind', payload '{"data":{},"error":"Failed to bind","status":"error","transaction":"ypt4h-1"}'
error 2025-08-30 18:02:10z2m: Failed to bind

• I found out, that the ezsp driver could be a problem with that. I guess the problem startet when I updatete either Z2M or Mosquitto.
• Would a change to ember help to solve this binding issues?

Here's what the webinterface of the Zigbee device says:

Tasmota
Information
Program Version	14.6.0.2 (76a39f7-zig_bridge32)
Build Date & Time	2025-06-07T12:48:34
Core/SDK Version	3_1_3/5.3.3.250501
Uptime	0T05:47:46
Flash Write Count	83
Boot Count	61
Restart Reason	Vbat power on reset
MAC Address	94:54:C5:EE:80:F9
IP Address (AP)	192.168.4.1
Gateway	192.168.4.1
AP2 Information	SSId
RSSI 100%, 0 dBm
Mode low rate
Channel 1
BSSId
Hostname	tasmota-EE80F8-0248
Hostname	tasmota-EE80F8-0248-eth
IPv6 Local (eth)	fe80::9654:c5ff:feee:80fb%en1
MAC Address	94:54:C5:EE:80:FB
IP Address (eth)	192.168.0.215
Gateway	192.168.0.1
Subnet Mask	255.255.255.0
DNS Server1	192.168.0.1
DNS Server2	0.0.0.0
HTTP API	Enabled
MQTT Host	
MQTT Port	1883
MQTT User	DVES_USER
MQTT Client	DVES_EE80F8
MQTT Topic	tasmota_%06X
MQTT Group Topic 1	cmnd/tasmotas/
MQTT Full Topic	cmnd/tasmota_EE80F8/
MQTT Fallback Topic	cmnd/DVES_EE80F8_fb/
MQTT No Retain	Disabled
ESP Chip Id	15630584 (ESP32-D0WD-V3 v3.1)
Flash Chip Id	0x1640EF (DIO)
Flash Size	4096 KB
Program Flash Size	4096 KB
Program Size	1414 KB
Free Program Space	1465 KB
Free Memory	152.0 KB (frag. 27%)
Partition safeboot	832 KB (used 92%)
Partition app0*	2880 KB (used 49%)
Partition fs	320 KB

And here's my about section from Z2M

Zigbee2MQTT version
[2.6.0]
Coordinator type
EZSP v8
Coordinator revision
6.7.10.0 build 423
Coordinator IEEE Address
0x1cc089fffece4fb3
Frontend version
0.9.19
zigbee-herdsman-converters version
24.11.0
zigbee-herdsman version
5.0.4

[rayanamal]

Hey there. Just set up my Sonoff ZBBridge (non-Pro) with Tasmota and Zigbee2MQTT on the HA. I see the same message. It seems like what Zigbee driver you need to run depends on the specific Zigbee chipset used in the Zigbee Bridge.

The Tasmota docs, among other sources, seem to indicate that:

• The Sonoff Zigbee Bridge (ZBBridge) (non-Pro) uses the EFR32MG21 chipset from Silicon Labs.
• The Eachen eWeLink ZBBridge Pro, the one you have, also uses the EFR32MG21.
• However, the newer Sonoff Zigbee Bridge Pro (ZBBridge-P) uses the ICC2652P chipset from Texas Instruments .

Each Zigbee chipset has to use a Zigbee protocol driver developed by the manufacturer. These are called "Zigbee stacks":

• EFR32/EM35x chips from Silicon Labs uses the EmberZNet stack, also called EZSP (EmberZNet Serial Protocol).
• Chips from Texas Instruments use the Z-Stack stack, also called ZNP (Zigbee Network Protocol).

Currently, there are 2 places in the documentation that you can end up when trying to configure your device that is named ZBBridge:

1. The first (and seemingly the most common one) is this one. It instructs to install with the now-deprecated ezsp driver.
2. The newer one linked to from the deprecation warning you mentioned is this one. It's focused on the new ember driver.

Going from this, it seems you can use the ember driver with your (and mine) ZBBridge. However, if you reload Zigbee2MQTT after setting the driver to ember, you get this error:

[2025-10-29 15:12:37] info: 	zh:ember: ======== Ember Adapter Starting ========
[2025-10-29 15:12:37] info: 	zh:ember:ezsp: ======== EZSP starting ========
[2025-10-29 15:12:37] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-10-29 15:12:37] info: 	zh:ember:uart:ash: Socket ready
[2025-10-29 15:12:37] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-10-29 15:12:38] info: 	zh:ember:uart:ash: ======== ASH connected ========
[2025-10-29 15:12:38] info: 	zh:ember:uart:ash: ======== ASH started ========
[2025-10-29 15:12:38] info: 	zh:ember:ezsp: ======== EZSP started ========
[2025-10-29 15:12:38] error: 	z2m: Error while starting zigbee-herdsman
[2025-10-29 15:12:38] error: 	z2m: Failed to start zigbee-herdsman
[2025-10-29 15:12:38] error: 	z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
[2025-10-29 15:12:38] error: 	z2m: Exiting...
[2025-10-29 15:12:38] error: 	z2m: Error: Adapter EZSP protocol version (8) is not supported by Host [13-17].

The last line is the important one. It means the EZSP protocol version of the adapter is not supported by the Host (which in our case is Zigbee2MQTT running with the ember driver). This means that unless a newer firmware image is available, we won't be able to use the ember driver on the ZBBridge devices using the EFR32 series chipset. The firmware we currently use is here: https://github.com/arendst/Tasmota/tree/development/tools/fw_SonoffZigbeeBridge_ezsp

If you are experiencing issues, you might try using the 6.7.9 firmware over there which contains additional bug fixes over the recommended 6.7.8 firmware.

Hopefully somebody will develop or release new firmware to fill in the gap. @arendst, is an update possible for ZBBridge devices running on EFR32 chips to support at least v13 of EZSP? I'm a total newbie in this.

[Micharius]

Hello again...withouth a response for a long time here and my patience running out, I went ahead and bought a SLZB-06p7U Zigbee Ethernet adapter, running zstack. Everything runs smoothly now.

[rayanamal]

Good for you. An update from me after about a week with Sonoff ZBBridge: I'm had occasional downtime with Zigbee2MQTT due to the flakiness of my home Wi-Fi, tbh I was tinkering with the router a little, but still.

I agree an ethernet-connected Zigbee bridge would provide the most ideal setup, being both decoupled from HA and connected to it in a reliable way.