Handheld Heater-Vibrator PCB Design

I’m developing a rechargeable, handheld device that delivers both heat and vibration therapy, and I need a complete, original electronics solution—from schematic through working prototype.

Core functionality
• Three user-selectable heating levels and three vibration levels, each set from its own dedicated button, with a separate power button.
• Eight LEDs that clearly indicate current heat level, vibration level, and remaining battery charge.
• USB-C charging for a single 3.7 V Li-ion cell, with built-in temperature monitoring and automatic overheating protection.

What I will supply
Photos of a comparable product, partial schematics, and a functional description so you can understand the concept; they are reference only—the new design must be wholly your own.

Your scope
Design the full electronics stack, program the firmware logic that drives the heater, motor, LEDs, safety cut-offs, and charging management, then deliver a fully assembled and tested prototype ready for field evaluation.

Deliverables
1. Electrical schematic (editable source)
2. Custom PCB layout with Gerber, pick-and-place, and drill files
3. Complete BOM with manufacturer part numbers and availability notes
4. Compiled firmware and well-commented source code
5. One working prototype validated for all functions
6. All original design files so I can iterate or scale manufacturing later

Acceptance criteria
• Device reaches and maintains each temperature setting within ±5 °C while never exceeding the safety threshold you define in firmware.
• Vibration intensities are distinct and reproducible.
• LED indicators reflect mode and battery status exactly as specified.
• Unit charges safely from standard 5 V USB-C supply and passes a 24-hour soak test.

Feel free to use KiCad, Altium, Eagle, or your preferred professional toolchain; just make sure all outputs are exportable. If this sounds like your kind of build, let’s discuss timelines and any questions you have before kicking off.