Variable Vibration Device Prototype

I want a wrist-sized electronic device that does one job exceptionally well: create vibrations—and let me vary those vibrations on demand based on button presses. The vibrations can have 3 differnt modes.

Scope
• Design the electronics: select a motor/actuator, driver circuit, microcontroller, power management, and safety components.
• Build a fully working prototype that produces variable vibration patterns (intensity, rhythm, and duration) through a simple user interface such as buttons, a rotary encoder, or touch pads.
• Deliver firmware that lets me adjust the vibration parameters without reprogramming; an onboard LED or small display for feedback is welcome but not mandatory.

Deliverables
1. Schematic, PCB layout (KiCad, Altium, or Eagle), and ready-to-order Gerber files.
2. Firmware source code (Arduino, ESP32, STM32, or another readily available platform) with clear comments.
3. Bill of materials with part numbers, suppliers, and estimated costs.
4. Assembled and tested prototype, plus short video or oscilloscope traces proving variable vibration performance.
5. Basic enclosure concept (STL or STEP) to show fit and finish; a 3D-printed shell is enough at this stage.

Acceptance criteria
• Device fits comfortably on wrist.
• Runs from a rechargeable Li-ion/Li-Po battery for at least 3-4 hours of continuous use.
• Generates at least three distinct vibration profiles selectable from the interface.
• All files compile, manufacture, and flash without modification.

If you already have experience with haptic drivers, ERM/LRA motors, low-power design, and rapid prototyping, I’d love to see examples. Looking forward to collaborating and fine-tuning this variable vibration gadget from concept to functional demo.