September 11, 2026
TSD is expanding the possibilities for compact human-machine interfaces with its new 1.8-inch Smart Knob Module, combining a high-resolution AMOLED display, rotary control, embedded processing and wireless connectivity in one compact device.
With a diameter of approximately 69 mm and a height of only 21.5 mm, the module provides designers with an alternative to conventional combinations of separate displays, buttons and rotary encoders. Instead, visual feedback and physical interaction are brought together directly at the point of control.
At the centre of the Smart Knob is a 1.8-inch circular AMOLED display with a 466 × 466 pixel resolution. TSD combines the display with an STM32U5F9 MCU, providing the processing performance required for responsive graphics and interactive HMI functions while maintaining the low-power characteristics needed for battery-operated designs. TSD first demonstrated the 1.8-inch platform at Embedded World 2026 and has since added it to its Smart HMI product roadmap.
A rotary controller becomes considerably more useful when the interface can change according to the function being controlled.
Instead of surrounding a mechanical knob with fixed markings, the AMOLED screen can dynamically display parameters such as temperature, speed, volume, operating mode, menu selections, system status or graphical indicators.
The rotary mechanism provides 36 tactile positions per revolution, giving the user physical feedback while navigating through settings. The combination of visual and tactile feedback can help create interfaces that remain intuitive even when one control is used for multiple functions.
For an engineer, that also means fewer dedicated controls may be required on the front panel. One Smart Knob can potentially replace several buttons, indicators and menu controls while still providing immediate feedback to the user.
The integrated STM32U5F9 provides the processing platform behind the Smart Knob. TSD introduced the 1.8-inch version specifically around this controller as the next step beyond its earlier 1.3-inch smart knob platform.
Local processing inside the module can simplify the overall HMI architecture because display handling and user-interface functions do not necessarily have to be handled entirely by the host processor.
This is particularly useful in applications where the Smart Knob operates as a dedicated user-interface subsystem connected to a larger embedded controller.
For developers, the architecture also opens possibilities for customised graphical interfaces, operating modes and application-specific interaction.
The Smart Knob is not limited to fixed, wired installations.
An integrated 800 mAh battery supports up to 15 days standby time and approximately 8 hours of continuous operation, depending on the application and operating conditions.
Charging is possible through USB Type-C at 5 V / 1 A, while magnetic wireless charging provides an alternative for applications where exposed connectors are undesirable or where the control needs to be removed regularly.
TSD officially highlights magnetic wireless charging as one of the key features of the new 1.8-inch platform.
Connectivity includes both Bluetooth and NFC, enabling communication with nearby equipment, mobile devices or other connected systems. TSD’s current Smart HMI roadmap also includes wireless BLE versions of the Smart Knob platform.
A fidget-spinner-style power switch is integrated into the design, further supporting the concept of a self-contained, portable HMI rather than a conventional panel-mounted rotary encoder.
The combination of display, rotary input, touch, embedded processing and wireless connectivity makes the Smart Knob suitable for a wide range of applications.
Potential use cases include industrial control systems, smart-home equipment, medical devices, laboratory equipment, audio systems, building automation and other connected products where designers want to reduce the number of physical controls without sacrificing usability.
TSD positions its wider Smart HMI portfolio for industrial, automotive, medical and smart-product applications. The 1.8-inch Smart Knob extends that approach into a compact circular interface that can be integrated as either a fixed or wireless control.
The interesting part of the Smart Knob is therefore not simply the circular AMOLED display.
By combining the 466 × 466 display, STM32U5F9 processing, 36-position rotary feedback, touch interaction, Bluetooth, NFC, battery operation and magnetic wireless charging, TSD turns the traditional rotary knob into a configurable HMI platform.
For product developers, this can reduce front-panel complexity while providing considerably more flexibility in how information and controls are presented to the user.
Interested in evaluating the TSD 1.8-inch Smart Knob for your next HMI design? Contact TOP-electronics to discuss the module, integration options and your application requirements.
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