Keypad Glass Door Auto-Lock

I need a compact “grendel tekan” style automatic latch that mounts cleanly on frameless glass doors. When the door closes the latch should engage itself; release happens only after a valid PIN is typed on the integrated keypad. Brown, white, and black finishes are all desirable so the mechanism blends with different interiors.

Scope of work
• Engineer the mechanical latch and housing for 10 mm–12 mm tempered glass, rated to resist at least 50 kg of pull force.
• Design the electronics: a low-noise motor or solenoid driver, back-lit keypad, secure PIN storage (minimum 50 user codes), and a simple 12 V or USB-C power input.
• Provide complete drawings, STEP/STL files, PCB schematics and Gerbers, a bill of materials, and well-commented firmware so a local workshop can build a prototype immediately.
• Include a concise installation and user guide.

Acceptance criteria
– Unlocks in under one second after correct code is entered
– Audible operation below 45 dB at one metre
– Cycle-tested for 100 000 opens/closes without failure
– All documentation delivered in English

If you have prior experience designing small electromechanical locks—especially for glass doors—your insight will be invaluable.