1. Prototypes Are Not Deployments
The first two versions worked technically but relied on a power bank and exposed wiring.
This was acceptable for testing but not for long-term integration.
Engineering maturity means moving from “it works” to “it belongs there.”
2. Power Integration Matters More Than Logic
The control logic was simple.
The real improvement came from integrating into the 24V lift supply using a buck converter.
Power architecture often defines system quality more than firmware complexity.
3. Isolation Is Critical in Unknown Systems
The elevator control circuitry was not fully documented.
Using a relay ensured electrical isolation between the microcontroller and the lift system.
When working with external control systems, assume unknown risk and design conservatively.
4. Iteration Quality > First Design
The first version solved the problem.
The third version solved it properly.
The biggest improvement was not in features — it was in integration cleanliness.
5. Future Improvements
- Replace relay with solid-state switching
- Add transient protection across terminals
- Implement watchdog for fail-safe reset
- Add local manual override switch
- Improve enclosure finishing