What I set out to build
I explored a pendulum-based desk product as a complete electromechanical system rather than only a mechanism. The concept brought together CAD, rotary sensing, motor selection, STM32 embedded control, PCB design, 3D-printed prototyping, and early production costing. Development stopped before a finished product, but the unfinished prototype became a practical introduction to multidisciplinary product engineering.
SYSTEM ARCHITECTURE
Mechanical product concept
pendulum mechanism + enclosure → CAD assembly → printable prototypeThe mechanical work translated the interaction concept into parts that could be assembled, adjusted, and produced through iterative 3D printing.
Sensing and embedded control
rotary position → STM32 timers and firmware → motor commandEncoder, timer, and motor-control research established how the controller could measure pendulum motion and drive the actuator with repeatable timing.
Electronics integration
controller + sensor + motor driver + power → schematic and PCB conceptComponent selection and schematic work moved the idea from a collection of development modules toward a compact electronics architecture.
Prototype and production thinking
prototype iteration → assembly choices → estimated unit costThe project considered fabrication and cost early enough to expose the difference between a working experiment and a repeatable product.
How the concept developed
- STAGE 01
Shape the product in CAD
Developed the pendulum mechanism and enclosure in CAD with 3D-printed prototyping and assembly in mind.
- STAGE 02
Select the electromechanical architecture
Compared microcontrollers, encoders, motors, and motor drivers before narrowing the embedded architecture around an STM32 development platform.
- STAGE 03
Develop the embedded and PCB direction
Studied timer configuration, encoder interfacing, and motor-speed control, then carried the selected components into schematic and PCB work.
- STAGE 04
Prototype and examine production cost
Documented the first prototype direction and estimated per-unit production cost to identify the largest practical constraints.
Key engineering decisions
Designing several systems at once
The mechanism, enclosure, sensor, motor, driver, firmware, and power path constrained one another. A mechanical change could alter sensing or torque requirements, while an electronics choice could change packaging and thermal needs.
Moving beyond development modules
Learning on an STM32 board was only the first step. Turning that setup into a PCB required attention to interfaces, power, connectors, component availability, and how the electronics would fit inside the CAD assembly.
Recognizing the remaining integration gap
Individual design threads advanced, but the project stopped before the mechanism, electronics, firmware, and enclosure were validated as one finished device. That gap is an important part of the project record.
What I completed
- The retained archive includes CAD and prototype work alongside component-selection notes for the controller, sensing, motor, and driver architecture.
- STM32 research covers core microcontroller structure, development tools, timers, encoder interfacing, and motor-speed control.
- Schematic and PCB work documents the move toward integrated electronics rather than a permanently breadboarded concept.
- Prototype and cost-estimation records show that fabrication, assembly, and production economics were considered before the design was complete.
What I took from it
A product is the interaction of its mechanism, electronics, firmware, enclosure, and manufacturing process; advancing only one layer does not complete the system.
STM32 timers, rotary sensing, motor drivers, PCB design, and mechanical packaging became easier to understand once they were tied to one physical product concept.
An unfinished prototype can still be valuable when the completed work, remaining integration gap, and lessons are presented honestly.