Lockbot

Lockbot is a robot attached to our door that makes it possible for trusted members who don't have a key to open the door. It consists of a servo motor, two gears, a potentiometer and an Arduino Uno + ethernet shield.

Microcontroller build instructions

Requires the platformio cli tool, follow these instructions to install it.

Next, in arduino/src, copy tokens.h.example to tokens.h and edit them if necessary.

Finally, in arduino, build and flash using the following:

. ~/.platformio/penv/bin/activate # Might depend on platform
pio run -t clean
pio run
pio run -t upload -t monitor

3D-print instructions

1. Install OpenSCAD
2. To print each lockbot part, open printfile.scad in OpenSCAD, uncomment the part you want to print, render it, export as STL then 3D print it. The big gear should be printed with 5 perimeter walls and solid infill, so it can handle the forces.

The NFC plate that holds the NFC cards is also included in this repository, see nfc_plate.scad. There's spacers for the motor in spacer.scad, this will need to be modified for different motors.

Components

• Arduino Uno + power supply for Arduino Uno (5V USB)
• Servo motor: TD-8130MG 360° Servo Motor - 30kg/cm + separate power supply for the servo motor
• Relay (also connected to motor power supply)
• Ethernet shield
• Buzzer
• Button
• 10k multiturn potentiometer

See lockbot.cpp for how to connect these components together.

Make sure that when turning the lock, the multiturn potentiometer does not go out of bounds (overturning it WILL break it).

Calibration

Before lockbot can be used, you'll need to calibrate 4 points using client.py <subcommand>

• calibrate_open_pos: the position you'd like lockbot to go to when opening the door
• calibrate_open_bnd: the last position where you consider the door as 'open'
• calibrate_close_bnd: the first position where you consider the door as 'locked'
• calibrate_close_pos: the position you'd like lockbot to go to when closing the door