diff --git a/elevator/.gitignore b/elevator/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/elevator/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/elevator/Cargo.lock b/elevator/Cargo.lock
new file mode 100644
index 0000000..18872f4
--- /dev/null
+++ b/elevator/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "elevator"
+version = "0.1.0"
diff --git a/elevator/Cargo.toml b/elevator/Cargo.toml
new file mode 100644
index 0000000..f7735f5
--- /dev/null
+++ b/elevator/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "elevator"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/elevator/src/main.rs b/elevator/src/main.rs
new file mode 100644
index 0000000..25c6f04
--- /dev/null
+++ b/elevator/src/main.rs
@@ -0,0 +1,59 @@
+#[derive(Debug)]
+/// An event in the elevator system that the controller must react to.
+enum Event {
+    Arrived(i32),
+    Called(i32, Direction),
+    Sent(i32),
+    DoorOpened,
+    DoorClosed,
+}
+
+/// A direction of travel.
+#[derive(Debug)]
+enum Direction {
+    Up,
+    Down,
+}
+
+/// The car has arrived on the given floor.
+fn car_arrived(floor: i32) -> Event {
+    Event::Arrived(floor)
+}
+
+/// The car doors have opened.
+fn car_door_opened() -> Event {
+    Event::DoorOpened
+}
+
+/// The car doors have closed.
+fn car_door_closed() -> Event {
+    Event::DoorClosed
+}
+
+/// A directional button was pressed in an elevator lobby on the given floor.
+fn lobby_call_button_pressed(floor: i32, dir: Direction) -> Event {
+    Event::Called(floor, dir)
+}
+
+/// A floor button was pressed in the elevator car.
+fn car_floor_button_pressed(floor: i32) -> Event {
+    Event::Sent(floor)
+}
+
+fn main() {
+    println!(
+        "A ground floor passenger has pressed the up button: {:?}",
+        lobby_call_button_pressed(0, Direction::Up)
+    );
+    println!(
+        "The car has arrived on the ground floor: {:?}",
+        car_arrived(0)
+    );
+    println!("The car door opened: {:?}", car_door_opened());
+    println!(
+        "A passenger has pressed the 3rd floor button: {:?}",
+        car_floor_button_pressed(3)
+    );
+    println!("The car door closed: {:?}", car_door_closed());
+    println!("The car has arrived on the 3rd floor: {:?}", car_arrived(3));
+}