Model combination lock with automatic relocking

A demonstration lock with a four-button sequence, debouncing and lockout after three errors.

Project components

• arduino Tutorial × 1
• button Tutorial × 1
• button Tutorial × 1
• button Tutorial × 1
• button Tutorial × 1
• buzzer Tutorial × 1
• servo Tutorial × 1
• usb-breakout Tutorial × 1
• capacitor-electrolytic Tutorial × 1