A smartwatch is a wearable computer in the form of a wristwatch; modern smartwatches provide a local touchscreen interface for daily use, while an associated smartphone app provides for management and telemetry (such as long-term biomonitoring). While early models could perform basic tasks, such as calculations, digital time telling, translations, and game-playing, 2010s smartwatches have more general functionality closer to smartphones, including mobile apps, a mobile operating system and WiFi/Bluetooth connectivity. Some smartwatches function as portable media players, with FM radio and playback of digital audio and video files via a Bluetooth headset. Some models, called ‘watch phones’ (or vice versa), have mobile cellular functionality like making calls.
While internal hardware varies, most have an electronic visual display, either backlit LCD or OLED. Some use transflective or electronic paper, to consume less power. They are generally powered by a rechargeable lithium-ion battery. Peripheral devices may include digital cameras, thermometers, accelerometers, pedometers, heart rate monitors, altimeters, barometers, compasses, GPS receivers, tiny speakers, and microSD cards, which are recognized as storage devices by many other kinds of computers.
Software may include digital maps, schedulers and personal organizers, calculators, and various kinds of watch faces. The watch may communicate with external devices such as sensors, wireless headsets, or a heads-up display. Like other computers, a smartwatch may collect information from internal or external sensors and it may control, or retrieve data from, other instruments or computers. It may support wireless technologies such as Bluetooth, Wi-Fi, and GPS. For many purposes, a “watch computer” serves as a front end for a remote system such as a smartphone, communicating with the smartphone using various wireless technologies. Smartwatches are advancing, especially their design, battery capacity, and health-related applications.
The first digital watch, which debuted in 1972, was the Pulsar manufactured by Hamilton Watch Company. “Pulsar” became a brand name which would later be acquired by Seiko in 1978. In 1982, a Pulsar watch (NL C01) was released which could store 24 digits, making it most likely the first watch with user-programmable memory, or “memorybank” watch. With the introduction of personal computers in the 1980s, Seiko began to develop computers in the form of watches. The Data 2000 watch (1983) came with an external keyboard for data-entry. Data was synced from the keyboard to the watch via electro-magnetic coupling (wireless docking). The name comes from its ability to store 2000 characters. The D409 was the first Seiko model with on-board data entry (via a miniature keyboard) and featured a dot matrix display. Its memory was tiny, at only 112 digits. It was released in 1984, in gold, silver and black. These models were followed by many others by Seiko during the 1980s, most notably the “RC Series”: During the 1980s, Casio began to market a successful line of “computer watches”, in addition to its calculator watches. Most notable was the Casio data bank series. Novelty “game watches”, such as the Nelsonic game watches, were also produced by Casio and other companies.
The RC-1000 Wrist Terminal was the first Seiko model to interface with a computer, and was released in 1984. It was developed by Seiko Epson and was powered by a computer on a chip. It was compatible with most of the popular PCs of that time, including Apple II, II+ and IIe, the Commodore 64, IBM PC, NEC 8201, Tandy Color Computer, Model 1000, 1200, 2000 and TRS-80 Model I, III, 4 and 4p. The RC-20 Wrist Computer was released in 1985, under the joint brand name “Seiko Epson”. It had a SMC84C00 8-bit Z-80 microprocessor; 8 KB of ROM and 2 KB of RAM. It had applications for scheduling, memos, and world time and a four-function calculator app. The dot-matrix LCD displayed 42×32 pixels, and more importantly, was touch-sensitive. Like the RC-1000, it could be connected to a personal computer, in this case through a proprietary cable. It was also notable in that it could be programmed, although its small display and limited storage severely limited application development. The RC-4000 PC Data graph also released in 1985, was dubbed the “world’s smallest computer terminal”. It had 2 KB of storage. The RC-4500 (1985), also known as the Wrist Mac, had the same features as the RC-4000, but came in a variety of bright, flashy colors.
The Timex Datalink wristwatch, was introduced in 1994. The early Timex Datalink Smartwatches realized a wireless data transfer mode to communicate with a PC. Appointments and contacts created with Microsoft Schedule+, the predecessor of MS Outlook, could be easily transmitted to the watch via a screen blinking light protocol.
In 1998, Steve Mann invented, designed, and built the world’s first Linux wristwatch, which he presented at IEEE ISSCC2000 on 7 February 2000, where he was named “the father of wearable computing”. See also Linux Journal, where Mann’s Linux wristwatch appeared on the cover and was the feature article of LJ Issue 75. Seiko launched the Ruputer in Japan – a wristwatch computer with a 3.6 MHz processor. It was not very successful, since instead of a touchscreen it used a joystick-like device to input characters (much like high scores in arcade games), and the small screen with a resolution at 102×64 in 4 greyscales made it hard to read large amounts of text. Outside of Japan, this watch was distributed as the Matsucom onHand PC. Despite the rather low demand, the Matsucom onHand PC was distributed until 2006, making it a smartwatch with a rather long life cycle. Ruputer and onHand PC applications are 100% compatible. This watch is sometimes considered the first smartwatch since it was the first watch to offer graphics display (albeit monochrome) and many 3rd party applications (mostly homebrew).
In 1999, Samsung launched the world’s first watch phone, the SPH-WP10. It had a protruding antenna, a monochrome LCD screen, and a 90-minutes of talk time with an integrated speaker and microphone.
In China, since around 2015, smartwatches have become widely used by schoolchildren. They are advertised on television throughout the country as a safety device whereby the child can call in case of emergency. The devices are commonly colorful and made of plastic. They normally have no display unless a button is pushed. These smartwatches have limited capability compared to other smartwatches; their main functions consist of being able to conduct calls, displaying of time, and sometimes have air temperature sensitivity. They cost around $100 to US$200.