How does a smartwatch work? | Functions of Smartwatches in 2022

18 Jul.,2022

20th May 2022: How does a smartwatch work -All the functions of a smartwatch are performed by MCU. MCU controls the various sensors and processing units such as CPU, sensors, Bluetooth or other chipsets, graphic processor, etc.


smart health watch

How does a smartwatch work? | Functions of Smartwatches in 2022

How does a smartwatch work? Or What are the Functions of Smartwatches? If you want to know this, then this is the right article for you. Here you may get all answers to your queries.

How does a smartwatch work? The answer is that the smartwatch is just like a doctor which all time monitors your health and at the proper time tells you that when the treatment is necessary.

Thus smartwatches have now become a too important device to keep you healthy, active, and fit in your hectic life schedule.

Smartwatches are provided with a touch screen interface and made in such a manner that they can work with their compatible smartphone.

▪︎What is smartwatch?

If you want to know how does a smartwatch work or the functions of smartwatches then first you need to know what is a smartwatch. If you are interested then read the below carefully.

Wristwatch +Smartphone =Smartwatch

The smartwatch is a wearable device on your wrist that acts as a combination of a smartphone and computer or laptop in the form of a watch. That can do most of the works which you would expect from these two devices.

•That means in general, the smartwatch provides extra features than the time of a regular wristwatch and they come with touchscreen interfaces.

If you want to buy the best smartwatch or fitness band then read the article Types of Smartwatches and Fitness Bands in 2022 with All Specifications.

Evolution of Smartwatches:

The history of a smartwatch will help you to understand why all the companies were involved in making smartwatches from the earlier times to till now.

YearName of The Companies Behind The Evolution of Smartwatches1972Hamilton Watch Company(later acquired by Seiko in 1978)1980Casio1994Timex1998Steve Mann, the person behind the evolution of smartwatches1999Samsung2003Fossil2010Sony Ericsson2013Startup Company Omate2014Apple Inc.

How The Evolution of Smartwatches Occur:

▪︎In 1972 – the first digital watch Pulsar launched by Hamilton Watch Company which was later acquired by Seiko in 1978.

▪︎In 1980 Casio began to start the “computer watches “.

▪︎In 1994 -Timex introduced the Timex Datalink wristwatch.

▪︎In 1998 -Steve Mann made the world’s first Linux wristwatch.

▪︎In 1999- Samsung launched the world’s first watch phone.

▪︎In 2003- Fossil released the Wrist PDA watch.

▪︎In 2010-Sony Ericsson launched the Sony Ericsson LiveView, wearable watch.

▪︎In 2013- the first smartwatch TrueSmart was launched by the startup Omate.

▪︎In 2014- Apple Inc. announced its first smartwatch Apple Watch and was released in 2015.

Evolution of Smartwatches

If you want to know more about the evolution of the smartwatch then see Wikipedia.

The early smartwatches could be able to do the basic jobs only, such as calculations, translations, digital time telling, and game-playing, etc.

▪︎After 2010 smartwatches have evolved to come closer to smartphones by performing some specific functions like app installation, WiFi or Bluetooth or LTE connectivity, music playing, making and receiving calls and messages, etc.

▪︎The smartwatches are evolving still now in their health apps like heart rate, sleep, workouts, and to perform like a pulse oximeter battery capacity, improvements, and designs also.


There is no such clear, hard and fix rule for the division of smartwatches that is to make their different types.

▪︎According to the functions the smartwatches can be divided into various types on the basis of their each and every function.

▪︎But according to the combination of looks and functionality broadly the smartwatches are of three main types: the Smartwatch, the Hybrid smartwatch, and the Fitness tracker.

Hybrid smartwatch:

Look of Traditional Watch + Function of Smartwatch = Hybrid Smartwatch

These watches use the minute and hour hands to alert you to your phone notifications, instead of touch screens of smartwatches.

It is a classic analog watch but with some specialty that made it different from the traditional analog wristwatch.

▪︎These watches have no such screen as the smartwatch.

▪︎They have Bluetooth to connect with the smartphone.

▪︎Here alerts are received through the vibration and alarms of the watch.

▪︎You can program the hands of the watch according to the important messages that you want to receive.

Fitness tracker:

Fitness trackers are just like smartwatches but their looks and prices are different from smartwatches.

▪︎But their main aim is to track your activities to reach you in the fitness goal and ultimately to keep you healthy and active in all aspects.

▪︎Why do you need a smartwatch:

Functions of Smartwatches

•Health: A smartwatch can monitor heart rate, body temperature, sleep, etc.

☆After the Corona pandemic, some smartwatches or fitness bands with a pulse ox sensor can also measure what is your normal SpO2 and PR(bpm)?

Now smartwatch can also help you like this way: Menstruation tracking 7 smartwatches to know how long is ovulation period

•Fitness: If you are a fitness frick or health-conscious or sports person then it can act as a pedometer, GPS tracker, calorie checker, weather forecaster, or even a compass for you.

•Alerts: Smartwatch gives SMS, call, and email alerts, etc. by synchronization with a smartphone.

•Security: Smartwatch can perform many functions in your security purposes with the help of GPS, SOS, emergency communications and user call detection, etc.

Before buying a smartwatch you must read Smartwatch Buying Guide in 2022

General Functions of Smartwatches:

The smartwatches are not only used only for health purposes, additionally, they give much more facilities that may ease your everyday life also. These are:

1. Apps:

The smartwatches are good enough to support various apps to ease your works. These apps are supported according to the functions of the smartwatches.

2. Notifications:

Notifications are one of the most important features of smartwatches. Because smartphones send all of your essential information in the form of notifications to your smartwatch. Not only that notification for your activities and movements are also available in your smartwatch.

3. Media Handling:

It is also another criteria of smartwatches to handle the media activity of your smartphone from your smartwatch.

•Such as when you are listening to music on your smartphone then you can control its volume from your smartwatch.

•Not only that it also gives you the facility to handle all social media like Facebook, WhatsApp, Twitter, etc. messages just right from your wrist.

4. GPS:

The GPS is another necessary feature of your smartwatch because it tracks your activities and gives you the alert according to location change to inform you rightly.

5. Long Battery Life:

The smartwatches are generally come with good battery life, at least to run throughout the day.

Health Monitoring Functions of Smartwatches:

There are some well-developed specialized sensors present in smartwatches that can monitor the major vital activity of your body. These vital activities are:

A. Heart Rate Monitoring:

The smartwatches like Apple Watch detect heart rate by photoplethysmography or PPG method.

•The blood is red because it reflects red light and absorbs green light. So when the heart beats and flows more blood in the wrist then absorption of more green light occurs. But in between heartbeat less absorption of green light happens.

•And these differences are tracked by the watch to monitor your heart rate whole the day.

B. Sleep Monitoring:

The sleep apnea patients stop and start breathing irregularly at the time of sleeping.

If they don’t treat this problem then several other health problems can arise in them.

So at first, it is very necessary to track this regularly. And this tracking can be done by a smartwatch.

Not only the sleep apnea smartwatch can also track the quality of your sleep and sleep stages also.

C. SpO2 Monitoring:

Blood oxygen level monitoring become another important factor after the Corona pandemic.

There are many smartwatches available that bear a pulse ox sensor in them which can detect the oxygen saturation level of blood by the reflectance oximetry method.

D. Stress Monitoring:

Some smartwatches possess sensors that can detect the sudden electrical changes in the sweat of your skin when you placed the palm over the face of the device.

By calculating the data of these changes along with the heart rate, sleep, and activity your smartwatch can track and monitor your stress level regularly.

E. Sedentary Lifestyle Monitoring:

Some smartwatches give this facility also. A sedentary lifestyle is a curse in our modern life. Because they invite the diseases like diabetes, obesity, heart disease and even premature death also.

If you have set your goal to follow your routine then the proactive alarm will alert you when you are seating or lying for a long time and thus you can understand that how does a smartwatch work.

Extra Functions of Smartwatches:

Apart from the general and health monitoring features of the smartwatches, there are some extra features present in smartwatches that may be proven to be beneficial for you. These are:

● Find things:

There are several apps present in the smartwatch which may help you to find your lost things if you connect them with your smartwatch. Such as your smartphone, other electronic devices, and even keys of your car also.

● Control home gadgets:

You can easily connect your home appliances, lights, fans, doors, etc. with your smartwatch and you can control them from outside the home.

●Personal Assistance:

Smartwatch can remind you of everything when you are busy with your work. Such as taking medicines, switch off the oven before sleeping, etc.

Your smartwatch can help you to navigate with the assistance of GPS and Google maps etc. Such as it can tell you to turn it in the right or left direction when you are walking.

▪︎What are the components of smartwatches?

This specific point is also necessary to understand how does a smartwatch work or the functions of smartwatches because components of smartwatches are neatly related to the functions and working procedures of a smartwatch.


•Hardware includes a display, digital cameras, heart rate monitors, thermometers, pedometers, barometers, altimeters, GPS trackers, speakers, altimeters, compasses, accelerometers, etc.


The software includes calculators, personal organizers, digital maps, schedulers, and many other watches faces also.

Sensors of Smartwatch:

Optical Sensors: Present for heart rate monitoring.

Motion Sensors: For counting of steps at the time of workout.

Bioimpedance Sensor: To alert in a sedentary lifestyle.

GPS Sensor: To track the location during activity.

Calorie Counter Sensor: To check the calorie at various times of the day.

Gesture Sensor: To detect body movements.

Operating System of Smartwatch:

Operating System or OS is the main part of smartwatches or smartphones.

Different types of smartwatches use different types of OS according to their brands. These are described below:

Tizen OS- It is a Linux-based OS mainly used in Samsung smartwatches.

Watch OS- Developed by Apple Inc. used in Apple watches.

Wear OS– Used in smartwatches and developed by Google Inc. It is a version of Android OS.

Selfish OS- Linux-based OS and used in selfies smartwatches.

Asteroid OS- It can be used as a replacement for Android OS.

External Devices:

Smartwatches can connect with other external devices like wireless headsets, heads up display, sensors, etc.


Smartwatches support much wireless connectivity like Bluetooth, WiFi, and GPS. How does a smartwatch work is also related to the connectivity of the smartwatch and smartphone both.

Components of Smartwatches



MCU(Micro Control Unit)All the functions of a smartwatch are performed by MCU.
MCU controls the various sensors and processing units such as CPU, sensors, Bluetooth or other chipsets, graphic processor, etc.Sensor It senses, gathers, and transmits data to the CPU.Display It shows the data in 1.63″ super AMOLED display 320×320 resolution. CPUIt holds a 1GHz dual-core along with other electronic parts and a motherboard. Memory It consists of 4 GB internal memory for storage and 512 MB RAM.LCD cable It connects the LCD with the motherboard of the CPUBattery CR2 (Chromium) lithium-ion or lithium metal battery with maximum usage of 2-3 days and minimum usage of 6 days.GPS, Bluetooth or Wi-Fi, NFC
(wireless chipset)It can detect and transfer data in Bluetooth or wi-fi of compatible devices near it.CaseIt contains a dial and gasket that provides support to the case and screws to properly fix the motherboard and other parts. BandIt holds the case properly with detaching facility. Camera 2 MP camera with autofocus and different resolutions and 720 videos at 30 fps.Buttons/KeysFor home, back, touch, etc. functions.

▪︎How does a smartwatch work?

The figure mentioned below will help you to understand how does a smartwatch work?

How does a smartwatch work

To understand how does a smartwatch work follow the steps below:

  1. At first, you need a smartphone to use a smartwatch. It can be any android or iPhone.
  2. Install the specific app which comes with the smartwatch, on your smartphone.
  3. Open that specific app accompanied by your smartphone and turn on the Bluetooth of your smartphone to synchronize both devices.
  4. Now both of your devices are connected and you may get notifications(like emails, SMS, phone calls or calendar appointments, etc.)from your smartphone to your smartwatch.
  5. Now can install a third-party app (like Spotify, Whats app, etc.) from there corresponding app store of the smartwatch.
  6. Thanks to these apps you can keep your smartphone permanently in your pocket and do all the work of it in your smartwatch.

●Your smartwatch is subject to charge and recharge so you can charge it through a good quality power bank that is compatible with your smartwatch. Also, keep this in your mind at the time of buying the best smartwatch.

●If you have satisfied to know that how does a smartwatch work or functions of smartwatches and go through the lists and then don’t do delay picking the right one for you.

Frequently Asked Questions(FAQ):

Here are some frequently asked questions about how does a smartwatch work:

1. Can a smartwatch work without a phone?

There are some smartwatches present in the market which are called cellular smartwatches, those smartwatches can work without a phone. But you have to bear some extra charges for that. These smartwatches can only perform the basic functions such as doing some text, and making phone calls apart from the Bluetooth zone etc. But these smartwatches are not long lasting in terms on holding the charge of its battery. These smartwatches if work for 8 hours it will be fair enough for you.

2. How do smart watches operate?

First, install the specific app of your smartwatch to your smartphone then open the app and turn on the Bluetooth of your smartphone. Now both the devices are connected and you may get notifications from your smartphone on your smartwatch. You can also install third-party apps like WhatsApp, Spotify, etc. from the app store of your smartwatch.