Power Architecture Evolution

Iteration 1 & 2

• Powered via USB power bank
• External cable exposed
• Portable but inelegant

Iteration 3

• Located unused 24V output rail inside lift control supply
• Added DC-DC buck converter (24V → 5V USB)
• Eliminated external power bank
• Cleaner installation

Switching Mechanism

All versions used a single-channel relay module to simulate a button press.

Design reasoning:

• Galvanic isolation
• Simple actuation logic
• Low firmware complexity

Future improvement:

• Replace relay with optocoupler or MOSFET for longevity