Smartwatches: Are they still leading the market?

The global wearable technology market was valued at US $70 billion in 2023 and is expected to hit $231 billion by 2032. “Hearables,” such as earbuds and headphones, constitute 61.3% of this market. Smartwatches witnessed a growth of 8% last year. With chip and sensor technology advances, smaller devices like smart rings are emerging as an alternative to watches — but the rings are not yet as mainstream.

Smartwatches are holding their own in the market and offer a different appeal. They’re versatile embedded systems with broad applications packed into one device. Smartwatches have a specific type of embedded system.

In this article, we will explore their software and hardware components and these wearable as an embedded device.

What is a smartwatch?

A smartwatch is a wearable microcomputer that resembles a wristwatch. It has an operating system with several features (including the date and time) that allow various apps to run on it. These apps are typically connected to the user’s smartphone.

Types of smartwatches

There are two broad categories of smartwatches: a phone companion and a fitness tracker.

The phone companion: These smartwatches act as extensions of the wearer’s smartphone, staying connected via Bluetooth. Most apps actively share data between the two devices. Common features include email notifications, calling, messaging, social media integration, calendar management, music control, mobile payments, and voice assistant functionality. While certain fitness tracking features might be present, they’re not the primary focus.
The fitness trackers: These smartwatches are primarily designed for health and fitness monitoring. They may not always connect or sync with a smartphone. Key features include heart-rate monitoring, step counting, sleep tracking, calorie counting, workout tracking, and GPS navigation. While some models may also offer phone companion attributes, they’re secondary features.

Beyond the two broad categories, there are several specific types of smartwatches designed for different needs:

Outdoor: Designed for outdoor enthusiasts, these rugged smartwatches are built for sports and adventure activities. They have advanced features like GPS, heart-rate monitoring, compass, altimeter, and barometer. These devices are typically made to withstand tough conditions and have extended battery life. Notable examples include the Suunto 7 and Garmin Fenix.
Medical: Similar to fitness trackers, these smartwatches are equipped with medical-grade sensors. They offer features like ECG, blood-pressure monitoring, blood-oxygen level monitoring, pulse and heart rate tracking, and sleep-apnea detection. These devices often sync with healthcare apps for comprehensive health management. Popular models include the Garmin Vivomove and the Apple Watch, which have ECG and blood-oxygen monitoring capabilities.
Fashion-friendly: These smartwatches prioritize style with a minimalistic design, offering only essential features like notifications, maps, music control, and activity tracking. Examples of fashion-focused smartwatches include the Fossil Gen 6 and Withings Steel HR.
Luxury: These high-end devices are crafted from premium materials and blend traditional watch aesthetics with modern smartwatch features. They often include calling, notifications, and activity tracking while maintaining a sophisticated appearance. Notable examples include the Apple Watch Hermès and Tag Heuer Connected.
Kids: Specifically designed for children, these smartwatches emphasize safety and entertainment. Key features include educational apps, games, a web browser, GPS tracking, voice calling, and parental controls. Examples include the Apple Watch SE (Kids Edition) and Garmin Vivofit Jr. 3.

Smartwatches can also be categorized into classic and hybrid styles:

Classic: These devices feature a fully digital design with a touchscreen display, multiple sensors, and often cellular connectivity. They offer extensive app support and a range of functionalities typically found in modern smartwatches.
Hybrid: Resembling conventional analog watches, hybrid smartwatches incorporate smart features like notifications, calling, and activity tracking within a classic design. Often made from premium materials, these devices combine the sophistication of luxury watches with select modern functionalities.

The features

Smartwatches offer a variety of features, with some being nearly universal across different types and brands. Standard features include notifications for emails, calls, messages, and social media, as well as Bluetooth and Wi-Fi connectivity. Many smartwatches also offer cellular connectivity, allowing them to make and receive calls and messages independently from a smartphone.

The fitness-based smartwatches usually offer heart-rate monitoring, step counting, sleep tracking, calorie tracking, GPS mapping, and navigation. Phone companion smartwatches often provide music control, display customization, voice assistants, mobile payments, weather updates, calendar apps, and water resistance.

The software

A smartwatch functions like a mini-computer on your wrist, operating through a dedicated system. Popular smartwatch operating systems include:

watchOS is exclusive to Apple smartwatches and integrates seamlessly with Apple’s ecosystem.
Wear OS, developed by Google and previously known as Android Wear, is widely used by various manufacturers. It’s an open system and the most prevalent in the wearable tech segment.
Samsung developed Tizen for its smartwatches, but has largely been replaced by Wear OS in newer models.
Garmin OS is designed specifically for Garmin’s outdoor and fitness smartwatches.
Fitbit OS powers Fitbit’s fitness and medical smartwatches.

Various applications run alongside the operating system, including apps related to messaging, maps, music, weather, calendars, payments, health monitoring, social media, as well as internet browsers, voice assistants, and Bluetooth utilities. Some smartwatches also use real-time operating systems (RTOS).

The operating system and apps are accessed through a user interface, which includes icons, menus, and hardware controls like touchscreens and buttons.

At the hardware level, smartwatches are supported by embedded firmware, which manages essential functions such as display management, Bluetooth, Wi-Fi, battery management, sensor data processing, and cellular connectivity. The firmware relies on hardware drivers for efficient communication between components and the operating system and libraries that implement specific functions and facilitate communication between apps and the OS.

The hardware

Smartwatches are miniaturized versions of smartphones, functioning as compact computers with specialized features. Like any embedded system, smartwatches integrate multiple hardware components to operate effectively. Key hardware elements of a smartwatch include:

Processor
Acts as the brain of the smartwatch, managing app performance and multitasking. Popular processors include the Snapdragon W5+ Gen 1, Snapdragon W5 Gen 1, Exynos W920, MediaTek, and Ambiq Micro. The Snapdragon W5+ Gen 1 and W5 Gen 1, developed by Qualcomm, are flagship platforms for high-end performance, AI capabilities, and extended battery life.

The Exynos W920, a 5nm processor from Samsung, is specifically designed for wearables. MediaTek produces processors primarily used in budget-friendly smartwatches, while Ambiq Micro specializes in ultra-low-power processors that enhance battery life. Nordic Semiconductors also provides processors for fitness trackers and simpler wearables.

Memory
As with other computers, smartwatches use RAM and storage memory. They typically use Low-Power DDR (LPDDR) RAM, optimized for mobile and embedded systems and balancing performance and battery efficiency. Typical smartwatches have 512MB to 2GB of LPDDR RAM, sufficient for their limited app load. For storage, smartwatches rely on flash memory, which is fast, durable, and retains data even when powered off. Flash memory typically ranges from 4 to 16GB, storing the operating system, firmware, drivers, libraries, apps, and app data.

Battery
Most smartwatches are powered by a rechargeable Lithium-ion battery, which is sealed within the device and integrated with other hardware components. These batteries are non-removable, so replacement requires professional service to disassemble the watch. Some watches may feature removable batteries, but these are typically high-density rechargeable units rather than standard coin or pouch cells.

Smartwatches use various types of Lithium-ion batteries, including Lithium-ion Polymer (Li-Po), Lithium-ion Cobalt Oxide (LiCoO2), Lithium-ion Nickel Manganese Cobalt Oxide (NMC), Lithium-ion Iron Phosphate (LiFePO4), and Lithium-ion Nickel Cobalt Aluminum Oxide (NCA). While these battery types differ in composition, they share similar energy density, rechargeability, and overall performance characteristics.

Battery capacities in smartwatches typically range from 200 to 400 mAh. However, models with larger displays or more powerful features may require 500 or 600 mAh batteries. While a higher capacity battery can extend the device’s operating time, it also increases the size of the smartwatch, potentially affecting its form factor. Battery life is influenced not only by capacity but also by factors such as processor efficiency, memory usage, display brightness, display type, and overall user behavior.

Display and touchscreen
Most smartwatches use AMOLED (Active Matrix Organic Light Emitting Diode) displays, which range in size from 1.2 inches to 1.5 inches. Although compact, this size provides sufficient screen space for displaying information and app icons. AMOLED displays offer several advantages, including the ability to produce deep blacks by turning off individual pixels to enhance the contrast. They’re also thin, flexible, and provide wide viewing angles. Note, AMOLED displays are more power-efficient than LCDs and other LED displays.

Wireless connectivity
Smartwatches generally come equipped with Bluetooth and Wi-Fi for wireless connectivity. Many models also offer standalone cellular connectivity, enabling the device to make and receive calls and messages independently of a smartphone. However, phone companion smartwatches might need more cellular capability, relying instead on the connected smartphone for communication.

Sensors
Smartwatches are equipped with various sensors, many of which are tailored to specific types of watches.

Common sensors include:

Accelerometer: Detects movement and orientation
Gyroscope: Measures rotational movement
Temperature sensor: Monitors ambient temperature
GPS: Tracks location and aids in navigation
Altimeter: Measures altitude
Barometer: Measures atmospheric pressure.
Ambient light sensor: Adjusts screen brightness based on lighting conditions
Compass: Provides directional orientation

Some watches also include advanced sensors for health and fitness monitoring, such as ECG, heart rate monitors, blood oxygen sensors, pulse sensors, step counters, calorie trackers, and body temperature sensors.

Speaker
Most smartwatches feature miniature piezoelectric speakers, which play music, deliver audio feedback, and allow users to interact with the device, such as using a voice assistant.

Microphone
Smartwatches typically include compact and lightweight MEMS (Micro-Electro-Mechanical Systems) microphones. These microphones are used for voice interaction, making calls, and recording audio.

SIM card slot
Smartwatches with cellular capabilities have a slot for a nano SIM card, allowing them to function independently of a smartphone for calls and messaging. Typically, these devices include only one SIM card slot.

Charging port
Rechargeable batteries power smartwatches and usually feature a magnetic charging port. The watch is placed on a magnetic charging base, ensuring proper alignment for secure and reliable charging.

Smartwatch design

Designing a smartwatch is a complex and iterative process that involves several key stages. Initially, engineers define the design and functionality of the smartwatch, focusing on its aesthetics, core functions, and the features or apps it should support. They also identify target users and learn about their needs and preferences.

Once the product goals are established, the next step is to select the appropriate hardware components. This includes choosing the processor, RAM, flash storage, battery, sensors, display, touchscreen, buttons, and other elements like the case and straps. These components are integrated onto a printed circuit board (PCB) and securely assembled into a sealed case.

Before assembly, the firmware, operating system, and essential apps are loaded onto the flash memory. Deciding on the operating system and developing or selecting the necessary apps, drivers, and libraries are crucial software considerations in the design process.

After the hardware and software elements are determined, a prototype is created, which undergoes comprehensive testing and quality assurance processes to ensure it meets all specifications and functions as intended. The device is then refined through these tests, leading to the final production version ready for market release.