Sonoff ZBMini - tiny relay module with Zigbee - interior, Home Assistant

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The Sonoff ZBMini is a tiny, in-box relay controlled via the Zigbee protocol. These models are characterised by their small dimensions of 42.6*42.6*20 mm and their ability to work with a light switch from an existing installation (bistable). As usually, I will present here connecting it to the Home Assistant via Zigbee2mqtt, I will not even test the manufacturer's gateway.

The topic assumes a basic knowledge of HA. I recommend my HA tutorial:
https://www.elektroda.pl/rtvforum/topic3777098.html

The product is available to buy for £10-15, which is quite a good price for a Zigbee product. It is generally accepted that WiFi is cheaper. Box:
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A relay up to 10A will do, but this is understandable due to its size.
Contents:
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There is nothing else in this kit.
Instructions:

... but we are not interested in it apart from entering pairing mode, as we will connect to our Home Assistant via Zigbee2mqtt.
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There is no problem with this, with me a new device is immediately detected: .
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Information:
[/tr] [td:9a274500bb] SONOFF [td] [td] Model [td] ZBMINI [td] Friendly name

0xe0798dfffed3b6f6
Device type	Router
Zigbee model	01MINIZB
Description	Zigbee two way smart switch
Supported status		Supported
IEEE address	0xe0798dfffed3b6f6
	. Network address	0xBB15
	Firmware build date	20200927
Vendor

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Communication works both ways, we can control the relay both from the physical switch and from the HA:
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Additionally, this device extends the reach of our Zigbee network.

Interior of Sonoff ZBMini .
This device uses Zigbee, there is nothing to flash inside... we are not changing the firmware here. Nevertheless, I will look inside anyway - out of sheer curiosity:
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As befits Sonoff products, the inside is slightly better than the cheapest pieces from Tuya. We have a visible varistor at the input, a filter capacitor, and there are two electrolytic capacitors behind the rectifier bridge too. I don't mention the fuse, because it is practically always there.
Then there is a non-isolated step-down converter.
The relay is a GOLDEN G2309-B, GN-1A-5L, 16A 250V.
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Now the underside of the PCB:
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From what I can see, the chip inside is the EFR32MG21 - nothing new, I often see it in this type of product.
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Those pins could be shortened....

Of course, there is still a 3.3V LDO and a transistor to switch the relay and an input circuit from controlling the switch.

Summary .
I rather have nothing to complain about here. You don't need to free this product from the cloud, as everything works from the Zigbee2MQTT site, and the interior is pretty good too. In the cheapest Tuya products one looks in vain for a varistor or there filter capacitor, and here the interior is a bit richer. The device pairing with HA is also quite simple, but don't forget the fact that you need an adapter and a server with HA....
Finally, I'll mention that this equipment, like other Zigbee products (except battery powered) extends the range of our Zigbee network.
Is it worth it? Your decision. If anyone reading has used the ZBMini, feel free to share your experiences.[/td][/td][/td][/td]