Quantity   Component name
1 × Teensy 3.2 Arduino-compatible microcontroller
1 × Short Micro USB cable Used to splice out leads for power
1 × 3D printer filament PLA works nicely
1 × Ribbon cable Long enough to run from the Teensy to the servo motor, the Hall effect sensor above the door, and outside the door
1 × Wire Resistors (Fixed) / Zero Ohm Jumpers
1 × Solder
1 × Shrink tubing
1 × Tape for mounting and wire management Electrical tape (for electronics), packaging tape (for the NFC board), and gaffer tape (for wire routing, to avoid tape residue) would be best
1 × Mounting putty For door handle and magnet (an alternative adhesive method may suffice)
1 × Small neodymium magnet Plus some sort of tab to mount the magnet just above the door
1 × A3144 Hall effect sensor
2 × Screws For door handle: Head no wider than 3/8", bore no wider than 3/16" (or modify the STLs for your own screws)
1 × USB cable (male-to-female) Long enough to reach from your electrical outlet to the spliced Teensy USB cable
2 × Nuts For door handle: 3/8" wide (between flats), thread for chosen screw (or modify the STLs for your own nuts)
1 × MIFARE DESFire EV1 NFC keycard(s) Authorizing multiple keycards is supported, so get as many as needed
1 × USB power supply Any phone charger with a USB Type-A output should work
1 × Adafruit PN532 Breakout Board NFC reader module
1 × RGB LED Optional, used to indicate authentication success (green) or failure (red)
1 × Resistor for red lead in RGB LED Optional (required for use with RGB LED)
2 × Resistors for green + blue leads in RGB LED Optional (required for use with RGB LED)
1 × High Torque MG996R Metal Gear Digital Servo Motor
1 × 1/8" Acrylic No smaller than 3.516" x 1.95"