TTK4145 Elevator

Elevator application for controlling n elevators across m floors in a distributed fashion, implemented in Elixir.

Documentation

mix docs

See design description and diagrams in docs/.

Running nodes

Copy .env.example to .env and fill in the values, then:

# Local dev — run in separate terminals
./scripts/start.sh --local 1
./scripts/start.sh --local 2

# Local dev — override simulator port per node
./scripts/start.sh --local 1 --port 15657
./scripts/start.sh --local 2 --port 15658

# Cluster — uses ELEVATOR_ID set by sync.sh in .bashrc
./scripts/start.sh

# Cluster — explicit ID override
./scripts/start.sh 1

# Cluster — explicit ID + simulator port override
./scripts/start.sh 1 --port 15658

Sim

The simulator supports the following options:

• --port — TCP port used to connect to the simulator (default: 15657). Change this to avoid conflicts; you can run multiple simulators on one machine by using different ports.
• --numfloors — Number of floors (2–9; default: 4).

Options passed on the command line (for example, ./SimElevatorServer --port 12345) override settings in simulator.con, which in turn override the program defaults. Place simulator.con in the same folder as the executable. Options are case-insensitive.

Default keyboard controls

• Up: qwertyui
• Down: sdfghjkl
• Cab: zxcvbnm,.
• Stop: p
• Obstruction: -
• Motor manual override: Down: 7, Stop: 8, Up: 9
• Move elevator back in bounds (away from the end-stop switches): 0

Up, Down, Cab and Stop buttons can be toggled (and held) using uppercase letters.

Run the simulator:

./server/SimElevatorServer

Deploying to remotes

Setup

cp scripts/.env.example scripts/.env
# Edit scripts/.env with SSHPASS and SYNC_DEST

# Edit scripts/hosts with elevator ID → user@host mappings

Sync files

# Sync to all configured elevators
./scripts/sync.sh --all

# Sync specific elevator IDs only
./scripts/sync.sh 25 26

# On each host after first sync:
./scripts/install.sh

Remote shells

# Open a tmux session with one pane per configured host
./scripts/open_remotes.sh --all

# Or open only selected elevators
./scripts/open_remotes.sh 25 26

Running open_remotes.sh again recreates the local tmux layout, while each remote pane re-attaches to the same remote elevator tmux session.

Packetloss

To simulate packetloss run

sudo ./scripts/packetloss.sh <percentage> -ie

• -i is incomming traffic
• -ois outgoing
• -eis Elixir/Erlang and autodetects Beam ports

LOC stats (Elixir)

Lib: 1074
Test: 585