1. Introduction
The SayoDevice OSU O3C is a compact, high-performance 3-key mini keyboard featuring a customizable knob and advanced Hall effect magnetic switches. Designed for precision and speed, it supports rapid trigger functionality and offers extensive customization options for various applications, including gaming, office tasks, and media control. This manual provides detailed instructions for setting up, operating, and maintaining your OSU O3C mini keyboard.

Figure 1: SayoDevice OSU O3C Mini Keyboard with screen displaying 'SayoDevice O3C V1.0 SayoDevice.com'.
2. Key Features
- High-Speed Connectivity: USB 2.0 with an 8000Hz polling rate for ultra-responsive input.
- Customizable Trigger Stroke: Adjust the key actuation point with precision, as short as 0.05mm.
- Rapid Trigger Support: Advanced functionality for quick key presses and releases.
- Magnetic Switch Compatibility: Supports any magnetic pole and magnetic axis, with simple one-click calibration.
- Integrated IPS Color Screen: A 0.96-inch display shows key travel, key counting, and other vital information.
- Personalized Screen Text: Customize the first line of text on the main screen, for example, with your user ID.
- Programmable Knob: The rotary knob can be assigned to various functions, such as scrolling through lists or controlling media.
- Plug and Play: No drivers required for basic functionality.

Figure 2: The OSU O3C Mini Keyboard is plug-and-play and suitable for office, gaming, customer service, media, and industrial control.
3. Specifications
| Feature | Detail |
|---|---|
| Model | OSU O3C |
| Interface Type | USB (Wired) |
| Operation Style | Mechanical (Magnetic Red Switches) |
| Polling Rate | 8000Hz |
| Trigger Stroke | Customizable, shortest 0.05mm |
| Display | 0.96-inch IPS Color Screen |
| Language | English |
| Keyboard Standard | Mini Keyboard (3 Keys + 1 Knob) |
| Application | Desktop, Laptop, Number, Tablet |
| Color | White |
| Connectivity | Type-C USB Cable |
| Dimensions (Approx.) | Length: 15cm, Width: 10cm, Height: 4cm |
| Weight (Approx.) | 0.152 kg |
4. Package Contents
Ensure all items are present upon unboxing:
- 1 x SayoDevice OSU O3C Mini Keyboard
- 1 x Type-C USB Cable
5. Setup Guide
The SayoDevice OSU O3C Mini Keyboard is designed for simple plug-and-play operation.
- Connect the Cable: Insert the Type-C end of the provided USB cable into the port on the mini keyboard.
- Connect to Device: Plug the standard USB-A end of the cable into an available USB port on your computer, laptop, or tablet.
- Automatic Recognition: Your operating system should automatically detect and install the necessary drivers. No manual driver installation is typically required.
- Initial Display: Upon successful connection, the IPS screen will display the device name and version (e.g., "SayoDevice O3C V1.0 SayoDevice.com").

Figure 3: The keyboard is plug-and-play, with the screen displaying trigger stroke settings.
6. Operation
6.1 Basic Key Functions
The three keys on the keyboard can be programmed to perform various functions. By default, they may be assigned to common commands. Refer to the customization section for remapping.

Figure 4: Examples of programmable functions for the keys and knob.
6.2 Knob Functions
The rotary knob can be configured for various actions. Common uses include volume control, scrolling, or navigating through menus. Its function is fully customizable.
6.3 IPS Screen Navigation
The 0.96-inch IPS screen provides visual feedback and access to settings. Use the keys and knob to navigate through the menu options displayed on the screen.

Figure 5: Screen displaying menu options for configuration.
7. Customization
7.1 Trigger Stroke and Rapid Trigger
The trigger stroke can be adjusted to your preference, with a minimum of 0.05mm. The Rapid Trigger feature allows for immediate re-actuation upon key release. These settings are accessible via the on-screen menu.
- Navigate to the 'Press' or 'Release' settings on the screen.
- Use the knob to adjust the desired actuation or release distance.
- Confirm your selection to save the changes.

Figure 6: Screen showing trigger stroke and deadzone settings.
7.2 Magnetic Axis Calibration
The keyboard supports various magnetic switches. Calibration is a simple process:
- Access the calibration menu through the screen.
- Follow the on-screen prompts, typically involving a single click to calibrate the magnetic axis.

Figure 7: Screen displaying magnetic axis calibration instructions.
7.3 Customizable Screen Text
The first line of text on the main screen can be personalized:
- Navigate to the display settings on the screen.
- Select the option to edit the custom text.
- Input your desired text (e.g., a personal ID or message).

Figure 8: Screen displaying customizable text.
7.4 Language Selection
The device supports multiple languages for its on-screen interface.
- Access the 'Language' option from the main menu.
- Select your preferred language (e.g., English).

Figure 9: Screen displaying language selection.
8. Maintenance
- Cleaning: Use a soft, dry cloth to wipe the keyboard surface. For stubborn dirt, a slightly damp cloth with mild soap can be used, ensuring no liquid enters the device.
- Keycaps: Keycaps can be carefully removed for cleaning or replacement. Use a keycap puller to avoid damage.
- Storage: Store the keyboard in a cool, dry place away from direct sunlight and extreme temperatures.
- Cable Care: Avoid sharp bends or excessive pulling on the USB cable to prevent damage.
9. Troubleshooting
9.1 Keyboard Not Responding
- Check Connection: Ensure the USB cable is securely connected to both the keyboard and your device. Try a different USB port.
- Restart Device: Disconnect the keyboard, restart your computer/laptop, and then reconnect the keyboard.
- Test on Another Device: If possible, test the keyboard on another computer to determine if the issue is with the keyboard or the original device.
9.2 Screen Not Displaying
- Power Check: Ensure the keyboard is properly powered via the USB connection.
- Brightness/Contrast: Check if there are any display settings within the keyboard's menu that might affect brightness or contrast.
9.3 Key Functions Incorrect
- Check Customization: Verify your key assignments in the keyboard's settings. It's possible a key was accidentally remapped.
- Reset Settings: If issues persist, consider performing a factory reset (if available in the menu) or recalibrating the magnetic switches.
10. User Tips
- Versatile Application: This mini keyboard is highly versatile and can be used across various platforms including desktops, laptops, and tablets.
- Wired Connection: The keyboard operates via a wired USB connection, ensuring stable and low-latency performance. It does not support Bluetooth.
- No Mouse Included: This product is a standalone mini keyboard and does not include a mouse.
11. Warranty and Support
For warranty information and technical support, please refer to the seller's policies or contact the manufacturer directly. Keep your purchase receipt as proof of purchase.





