Interface
The main way to connect a wearable gadget with external devices. For smartwatches and fitness bands (see "Type"), this refers to a connection to a smartphone or tablet, while in the case of watch-phones, it usually refers to headsets.
— Bluetooth. Wireless technology for direct communication of various devices with each other. This is the most popular interface in smartwatches and bracelets: Bluetooth modules can be made very tiny, the communication range even in the earliest versions reaches 10 m, and different generations of Bluetooth are mutually compatible in terms of basic functionality. Specifically, the versions nowadays are as follows:
- v2.0. The earliest standard used in modern wearable gadgets. The possibilities of such a connection are more modest than those of more advanced versions, but they are often quite enough.
- v3.0. A standard that combines classic Bluetooth v 2.0 and a high-speed “add-on” for transferring large amounts of data.
- v4.0. Further, after 3.0, improvement of Bluetooth: in addition to the classic and high-speed format, this version added Bluetooth Low Energy technology. Support of this technology is especially useful in fitness trackers, which usually transmit small amounts of data, but constantly.
- v4.1. Modification of the 4.0 standard described above with improved protection against interference while working with LTE mobile communication...s.
- v4.2. Another improvement of the 4.0 standard, which introduced, in particular, improved data protection and increased connection speed.
- — v 5. The fifth generation of Bluetooth was released in 2016. The key innovation in version 5.0 was the expansion of capabilities related to the Internet of Things. Thus, in the Bluetooth Low Energy protocol, it became possible to double the data transfer rate (up to 2 Mbit/s) at the cost of reducing the range, and also quadruple the range at the cost of reducing the speed; In addition, a number of improvements have been introduced regarding simultaneous work with a large number of connected devices.
- — v 5.1. Update of the version described above v 5.0. In addition to general improvements in the quality and reliability of communication, this update introduced such an interesting feature as determining the direction from which the Bluetooth signal is coming. This makes it possible to determine the location of connected devices with centimeter accuracy.
- —v 5.2. The next, after 5.1, is the fifth generation Bluetooth update. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
- —v 5.3. The Bluetooth v 5.3 wireless communication protocol was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are evident in it.
Of course, to use all the capabilities of a particular version of Bluetooth, it must be supported not only by the gadget itself, but also by the smartphone/tablet to which it is connected.
SIM card support
Type
of SIM card for which the gadget is designed. SIM cards are required for mobile communication modules, which are mainly found in watch phones and children's beacons (see "Type"). And their types can be:
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Micro-SIM. Reduced in size and improved, in comparison with the obsolete mini-SIM, a variety of SIM-cards: the dimensions were reduced to 15x12 mm, while the amount of built-in memory and the overall functionality of the chip were slightly expanded.
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Nano-SIM. The newest and smallest variety of replaceable SIM-cards: it has dimensions of only 12x9 mm.
It is worth noting that nowadays, most mobile operators sell SIM cards that are compatible with all three types of slots at once: the chip itself has a nano-SIM format, and such a card can be installed in a micro-SIM or mini-SIM slot using an adapter frame. So paying attention to the type of SIM card makes sense, first of all, if you already have a "sim card" of a strictly defined format and you do not want to change it.
A separate variety is represented by
e-SIM(Embedded SIM) — non-removable modules that need to be programmed for a particular mobile operator. On the one hand, this creates some inconvenience: to change the number, changing the SIM card can be easier than reconfiguring the e-SIM. On the other hand, e-SIMs are more
...compact and better suited for wearable gadgets, and when you change your number, you do not need to spend money on buying a new card. The compatibility of such a module with the network of a particular operator should be specified separately.Type
The type of display installed in the watch/bracelet.
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Colour. Such displays are often found in classic smartwatches and are almost mandatory for watch phones (see "Type"). They allow you to display a wide variety of types of information — not only numbers or indicators, but also pictures, videos, web pages, etc. Among the shortcomings of colour displays in this case are high power consumption (which negatively affects the battery life of the device), as well as a rather high cost.
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Monochrome. There are two types of screens in this category. The first is single-colour displays, like those sometimes found on miniature MP3 players. They are significantly inferior in versatility to full-colour versions and can display only text and simple graphics, but they are cheaper and consume less power. This option is found among fitness trackers (see "Type"). Another variety of "monochrome" is e-ink, "electronic paper", known primarily from electronic books. Such displays can even be used in smartwatches — in addition to the actual colour, they are inferior to the colour versions only in the refresh rate, while consuming much less energy. The main disadvantage of e-ink is the rather high cost.
— Is absent. The complete
absence of a display is typical primarily for fitness trackers (see "Type"): the main purpose of such accessories is to colle
...ct information, and other methods are often enough for notifications — the simplest light indicators, sound signals, vibration, etc. Another specific type of non-display device is the smartwatch in the form of a conventional "hand watch" supplemented with indicators on the dial and/or other means of notification.Display type
— TFT. The simplest type of liquid crystal panel used in colour displays. They provide a relatively low, but generally sufficient image quality, while they are much cheaper than more advanced options. This type does not require backlight — more precisely, the backlight is part of the screen itself and turns on with it. Of the unequivocal disadvantages, it is worth noting that many
TFT panels have rather limited viewing angles; however, as technology improves, this drawback is gradually eliminated.
— IPS. A variety of LCD panels created in an attempt to eliminate the shortcomings of TFT. There are many subspecies
of IPS panels, but they all feature high colour reproduction quality, excellent brightness and wide viewing angles. The disadvantage of this option is the relatively high cost.
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OLED. In this case, we mean the technology used to create the simplest monochrome displays. In such screens, each segment that makes up the image is a separate LED, which eliminates the need for external illumination (and even the display itself can be used as a
flashlight).
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AMOLED. Screens based on a panel of active organic light emitting diodes. Similar to various types of TFT, this technology allows the creation of high-resolution colour displays. Its key feature is that
...the screen does not require a separate backlight system — in AMOLED panels, each pixel glows independently, resulting in somewhat lower power consumption. At the same time, such screens are distinguished by good colour reproduction quality, excellent brightness and wide viewing angles, however, they are much more expensive than TFT.
— Super AMOLED. An enhanced version of the AMOLED technology described above, delivering more expansive colour reproduction and brightness, as well as improved touch accuracy and speed, all at a thinner display and lower power consumption. In addition, the degree of reflection of external light is reduced, such a panel gives less glare and is better visible in sunlight.
— E-Ink (E-Paper). Displays made using "electronic paper" technology; in addition, this category also includes screens such as Memory LCD. The classic E-Ink screen is black and white, does not have a backlight (however, it can be built into particular gadgets), has a very low refresh rate and is poorly suited even for stopwatches, not to mention videos or animated pictures. On the other hand, "electronic paper" is perfectly visible in bright light and has a very low power consumption: it requires electricity only when the image is changed, while a still image remains visible even when the power is completely turned off. Memory LCD screens, in turn, with the same advantages, are almost as good as classic LCD panels in terms of refresh rate, but for a number of reasons they are not widely used.
— Transflective. A specific type of LCD panels that can work both due to its own backlight and due to reflected light. In bright external light (for example, in the sun), such a screen effectively reflects it and does not require a separate backlight — however, it is still included in the design and turns on in low light. This type of operation can significantly reduce power consumption compared to traditional LCD screens, where the image is not visible without backlight; in addition, good visibility in bright light is also an important advantage. The main disadvantage of panels of this type is their high cost; in addition, they are made mostly monochrome.
- LTPO. OLED and AMOLED matrices with an adaptive refresh rate that varies over a wide range based on the tasks performed. When rendering dynamic frames, screens with LTPO technology automatically raise the refresh rate to the maximum values, while viewing static images, they automatically reduce it to the minimum. At the heart of the technology is a traditional LTPS substrate with a thin TFT oxide film on top of the TFT base. Dynamic control of the refresh rate is provided by controlling the electron flow. The key benefit of LTPO screens is their reduced power consumption.Size
The size of the display installed in the gadget; for round screens, respectively, the diameter is indicated.
A larger screen, on the one hand, is more convenient to use, on the other hand, it significantly affects the dimensions of the entire device, which is especially critical for wearable gadgets. Therefore, manufacturers choose the display size in accordance with the purpose and functionality of each specific model — so that there is enough space on the screen and the device itself is not too bulky.
It is also worth mentioning that screens with a similar size may have different aspect ratios. For example, traditional smartwatches are usually equipped with square or round panels, while in fitness trackers, screens are often made elongated in height.
Screen resolution
Screen size in dots (pixels) horizontally and vertically. In general, this is one of the indicators that determine the image quality: the higher the resolution, the clearer and smoother the picture on the screen (with the same size), the less noticeable are the individual dots. On the other hand, an increase in the number of pixels affects the cost of displays, their power consumption and requirements for a hardware platform (more powerful hardware is required, which itself will cost more). In addition, the specifics of using smartwatches is such that there is simply no need to install high-resolution screens in them. Therefore, modern wrist accessories use displays with a relatively low resolution: for example, 320x320 with a size of about 1.6" is considered quite sufficient even for premium watches.
CPU frequency
The clock speed of the processor (CPU) installed in the gadget.
Theoretically, a high clock speed has a positive effect on speed and performance; however, in fact, this parameter has a purely reference and promotional value. This is due to the fact that the real capabilities of the CPU depend on a number of other factors, and the overall performance of the system also depends on the properties of the rest of the hardware. In addition, manufacturers select processors in such a way that their performance is guaranteed to be sufficient, taking into account the planned specialization and functionality of the gadget. Therefore, when choosing this parameter, you can not pay much attention.
Processor cores
The number of cores in the gadget's processor.
The core is the part of the processor responsible for processing a single stream of instructions. Accordingly, multiple cores allow you to handle multiple threads at the same time, which makes the processor multitasking and improves its performance. However, note that the presence of 2 or even 4 cores does not guarantee high computing power even for CPU itself — it often happens that an advanced dual-core chip works faster than an inexpensive quad-core one. In addition, the actual performance and speed of the system depends on many other specs that are not related to the processor. Therefore, the number of cores is solely for reference and marketing information, in itself it cannot be a basis for evaluating a gadget and comparing it with other models.
Device charging
The method of charging the battery provided in the gadget.
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MicroUSB. Charging via standard microUSB port. The main advantage of this option is the ability to charge from any microUSB cable or charger with such a connector, not necessarily branded. On the other hand, the connector itself is quite large by the standards of wrist devices and can significantly affect the increase in the dimensions of the gadget.
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USB type C. A compact version of the USB interface with a reversible design that allows the plug to be inserted in either direction. The USB type C specification provides for a number of advanced power options - in particular, various fast charging technologies have been developed for this connector.
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Branded connector. Charging via a cable that connects to the watch using the original proprietary interface. The other end of the cable, as a rule, has a standard interface - most often USB, which allows you to use any computer port or network adapter with such a connector for charging. Branded connectors can be smaller than microUSB, and fit better into the layout of the clock. However, for charging, as a rule, you have to use only original accessories, including branded cradles-stands, which are intended mainly for permanent stay in one place.
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Wireless. The main advantage o
...f wireless charging technology is the absence of any connectors - which is important, given the miniature size of wrist gadgets. At the same time, this method takes more time and significantly affects the cost of the device. Note that wireless charging is not contactless: the corresponding chargers can take the form of a stand or platform on which you need to put the watch, or a magnet attached to the back cover of the gadget, etc.
- Magnetic. Charging via a cable with convex metal contacts that are magnetized to the connector on the back cover of the wearable gadget. The magnetic contact group has no gaps, which improves the dust and moisture protection qualities of the smartwatch, and the charging plug itself is attracted to the magnetic connector, eliminating the need to look for the correct position for connecting the cable.
- USB A connector. The presence of a built-in connector allows you to connect the gadget directly to the charger, laptop, power bank without using additional cables.