May. 22, 2026 – M5Stack, a global leader in modular IoT and embedded development platforms, today announced the launch of StopWatch, a round AMOLED-based expressive interface for interactive IoT applications.
Built on the ESP32-S3R8, StopWatch is a compact development board featuring a 1.75" round AMOLED touch display, programmable buttons, vibration feedback, audio input/output, IMU motion sensing, RTC timekeeping, and multiple expansion interfaces, enabling responsive human-machine interaction in a compact form factor.
With the M5PM1 multi-stage power management system and a built-in 450mAh battery, StopWatch supports reliable standalone operation across portable smart devices, wearable projects, and lightweight AIoT applications.
Key Features
Upgraded Core
Powered by ESP32-S3R8, StopWatch provides 16MB Flash and 8MB PSRAM for graphics-intensive interfaces and advanced applications. Integrated 2.4GHz Wi-Fi supports wireless connectivity for IoT development.
Enhanced Visuals
StopWatch features a 1.75" round AMOLED touch display with 466×466 resolution, delivering high refresh performance, vivid color reproduction, and strong contrast for smooth and responsive on-device visual experiences.
Interactive Hardware
To support responsive HMI, StopWatch integrates programmable buttons, vibration feedback, audio input/output, and a 6-axis IMU for motion sensing. RTC support is included for time-aware applications.
Optimized Power
The built-in M5PM1 multi-stage power management system and 450mAh battery ensure stable standalone operation with efficient power usage for portable scenarios.
Flexible Expansion
StopWatch includes a HY2.0-4P interface and rear expansion headers for prototyping and peripheral integration, along with lanyard and magnetic mounting options for flexible deployment.
Detailed Specification
Further Development Potential
The built-in round AMOLED interface enables more expressive and flexible visual design, making StopWatch well-suited for portable smart devices, electronic badges, and lightweight IoT terminals where clear and engaging on-device visuals are essential.
Multi-Form Interaction Capability
With support for motion sensing, haptic feedback, time awareness, and flexible input options, StopWatch opens up diverse interaction possibilities for wearable devices, handheld controllers, and context-aware embedded applications.
UI Development Possibility
StopWatch provides ready-to-use libraries and examples, with compatibility for popular tools such as LVGL and SquareLine Studio, enabling flexible UI development workflows and rapid prototyping of custom interfaces.