Smart USB adapter with WLAN from Sonoff in the test

The smart USB adapter from Sonoff serves as a compact and inexpensive alternative to classic WLAN sockets. TechStage tested it and reveals when it is worth buying.

If you want to switch devices on and off using a call, smartphone or schedule, you usually use a WLAN socket (guide). The smart sockets enable the integration of stupid electricity consumers in the smart home and control via Google Assistant, Alexa & Co.

However, if the adapter plug is in a classic multiple socket, it quickly becomes tight. Most models are simply too bulky and block the space of the neighboring box. The smart WiFi USB adapter from Sonoff promises a cheap way out. It is located between the USB power supply and 5 V consumers such as table fans (advice), surveillance cameras (test winner), effect lights (advice) or, for example, chargers from inexpensive RC toys (advice).

The connection to the home network is made exclusively via WLAN in the 2.4 GHz band; the 5 GHz band is not supported. However, problems only arise if the supported frequency range on site is completely overflowing – keyword residential complexes in the city center. The manufacturer promises compatibility with Amazon’s Echo or Alexa and the option of remote control and programming of switching schedules via a free smartphone app for Android and iOS. Remote access via the mobile phone runs after prior registration via external servers.

The adapter sits between the power supply and the consumer.

A larger limitation is the maximum current of 2.5 A. The device can therefore not be used for devices with a high consumption or for charging with a quick charge function. This power is sufficient for the connected IP cameras, RC chargers and lamps in the test. The connected notebook also charges, but only with the handbrake on. The charging process takes correspondingly longer.

The buyer should have a certain willingness to take risks: The USB adapter does not offer a TÜV seal or CE certificate, so commercial trade in Germany is not permitted. In fact, the import is still possible and the device is also bought, which is why we give it a chance despite the lack of a security seal. Attention: We cannot carry out the tests of the testing organizations, in this test report we therefore restrict ourselves to the range of functions and practical experience, but do not go into any detail about the potential safety risks such as spontaneous combustion or damage to connected devices.

The dimensions of the white adapter plug are very compact at 4.5 × 3 × 2.6 cm. This is also reflected in the low weight of just 17 g. The manufacturer refers to the eWeLink app for control and programming. The matching Amazon Echo skill can also be found under the same name. We will try out how well these solutions work in the following.

The delivery takes place in a small cardboard box. It contains the adapter plug, proof of quality control including the warranty card and brief instructions. Even if this is extremely short, the text is even printed in German.

The scope of delivery of the USB adapter.

If you want more detailed information, scan the QR code on the side of the packaging and then open forwarded. There is actually a very comprehensive set-up guide via the smartphone app and an overview of why the app needs which access rights under Android. It is precisely this point that is not commonplace for cheap Chinese products and is extremely welcome in terms of information content from a data protection perspective.

The QR code for the download of the smartphone app leads our Android device directly to an APK file. Installation is therefore not possible with the secure standard smartphone settings; why Sonoff regulates this is a mystery to us. Because the app is also available in the official Google app store. Only in the printed operating instructions is there another QR code that goes directly to the eWeLink app in Google Playstore linked. The app itself is multilingual and also available in German.

The design and the operating options of the simple, white adapter plug are rudimentary. There is a small button on the side for manual switching on and off. Those who normally plug and unplug their USB devices usually appreciate that too. There are also two status LEDs. The white LED shows whether the socket is switched on or off. The green status LED indicates whether the adapter is connected to a WLAN. The LEDs cannot be dimmed or switched off, but this is bearable due to the very low luminosity. The lights are barely visible in bright surroundings.

The setup works pleasantly smoothly. The eWeLink app is available in German, but sometimes there is a term that has not been translated from English. However, it should be clear to the buyer from the outset that the German is sometimes wooden and does not always reveal which function is hidden behind a specific button. With basic rudimentary knowledge of WLAN and smart home, the device works right away, provided a 2.4 GHz WLAN is available. As mentioned, 5 GHz connections are not possible.

A possible application is the switching on and off of IP cameras.

At the beginning, the app prompts for registration using an email address and password, followed by the automatic dispatch of a one-time, four-digit registration code. This is valid for 30 minutes and is entered in the next step together with the login data just defined. The control of the smart USB adapter runs via an external server and should only work as long as it is in operation. However, since this uncertainty also goes hand in hand with many other smart home products on the domestic market, it may not be so bad for beginners to try to find the cheapest possible products. With the exception of a few very large providers, it is difficult to predict who will actually survive the highly competitive market.

The next step is the coupling between the adapter and the router. The power button is pressed for a little more than five seconds. Now the desired WLAN is selected. After entering the WiFi password, the eWeLink app requests some basic access rights under Android. The rest of the coupling happens automatically. After the name has been assigned to the device that has just been integrated, it appears in the app, can be switched or programmed manually and can also be accessed remotely via the smartphone.

With other smart home devices, we sometimes needed several passes to integrate them in order to achieve full operational readiness. In this respect, we consider the problem-free set-up to be a pleasant surprise.

The range of functions of the USB adapter is rudimentary and significantly less extensive than, for example, the Fritz! DECT 210 WLAN socket (test report). However, anyone who only plans to have connected consumers automatically switched at certain times, according to a weekly schedule or a countdown timer, will get a cheap and very compact solution. All settings are made via the eWeLink app on the Android or iOS-based smartphone or tablet. There is no user interface that can be called up using a web browser.

The size is also not a problem at multiple sockets.

After touching the connected device, three different main functional areas are available: Divide, Schedule and Timer.

Schedule defines one-off or repetitive on or off switching processes. Their time can be determined to the minute for every day. If a repetitive process is selected, the area for setting the date turns gray and only times are set. For this it is now possible to select individual days of the week. Differentiated switching times for different days of the week are possible if different events are created for part of the weekdays.

A simple countdown is hidden behind the timer option. After a freely configurable period of time, the USB socket then switches on or off. This option can also be adjusted to the minute. The maximum value is 366 days. By combining several countdown timers, the user can set up a random switching pattern, for example to simulate his presence.

The share button makes it possible to share the control of the adapter plug with other people. They also need an account with eWeLink. If the target user accepts the invitation, the smart socket appears in the app after two to three seconds and is ready for use. How far the control over the adapter plug should go is determined by the user via access rights. In the test, everything worked right away.

Basic setting options, such as changing the password or language, can be found on the main page behind a head symbol. An icon consisting of four squares provides access to a function for grouping several devices. Of course, this is not very exciting with a single device, but when using several compatible smart home devices, these can, for example, be grouped together in a living room group, for example, to be controlled together by call. How exactly is grouped can be determined at will. For example, different devices from different rooms in the same group are also possible.

It is also possible to set triggers that trigger a switching event for a group: This can be, for example, a movement, a noise or reaching a certain temperature.

Setup and control are straightforward.

The integration into the Amazon Alexa voice control works without any problems in the test. After activating the eWeLink skill, the adapter plug is recognized straight away. Only the entry of the registration data of the eWeLink account is still necessary, the adapter plug already appears in the Smart Home area of ​​Alexa and can be managed there.

The USB adapter compared to a WLAN socket.

The prices on the German market are around ten euros. On Ebay the smart adapter is available from six euros.

At this point, we have to point out the risks of a missing TÜV or CE seal again. Here everyone has to decide for themselves to what extent they can trust the manufacturer even without certificates. From personal experience, the devices from Sonoff work reliably.

The purchase of the smart USB adapter is particularly worthwhile if USB devices are to be controlled remotely and there is little space available. Even those who only want to retrofit fans (advisors), surveillance cameras (test winners), effect lights (advisers) or other consumers with an on-off button are well advised with the device. The uncomplicated handling and simple setup speak for the adapter.

Ultimately, the adapter plug is a more compact alternative to the classic WLAN socket (guide). Since some of these are also available from around 10 euros, the USB adapter remains primarily the size advantage.