Learning Goals 3 min
By the end of this lesson you will be able to:
- Build the swimming Plesiosaurus with its Medium Motor in port A.
- Tell apart the three sound blocks: play beep (60) for (0.2) seconds, play sound [Communication / Hello v] until done and play beep (60) for (0.5) seconds.
- Choose the right sound for each part of a paddling motion.
Meet the Model — the Plesiosaurus 6 min
What is a Plesiosaurus?
Plesiosaurus was a long-necked reptile that swam the seas during the age of the dinosaurs. It was not a dinosaur itself. It pulled itself through the water using four large, paddle-like flippers.
The science behind it
Plesiosaurus was a marine reptile, not a dinosaur. It breathed air but lived in the sea. Its four broad flippers beat up and down, almost like underwater wings, to push it forward. Its very long neck helped it reach fish.
Where you meet it
You meet it in the famous Loch Ness Monster legend, which some people imagine looks like a Plesiosaurus. Its skeletons are also displayed in museums.
What we'll build
We'll build a swimming Plesiosaurus. One Medium Motor on port A paddles its limbs so it moves forward. Then we explore three different kinds of sound.
Warm-Up 4 min
You have used a beep, a sound clip and a note. Today you compare all three side by side.
Quick-fire puzzle
Mei Ling runs this. How many different kinds of sound does she hear?
when program starts :: events hat play beep (60) for (0.2) seconds :: sound play beep (60) for (0.5) seconds :: sound play sound [Communication / Hello v] until done :: sound
Reveal the answer
Three. A plain beep, a musical note, and a recorded sound clip ("Hello"). Each block is a different kind of sound — and you choose which fits the moment.
New Concept — three ways to make a sound 10 min
The Brick can make three kinds of sound. Knowing which to reach for is like a musician choosing an instrument.
Blocks reference
| Block | Category | What it does |
|---|---|---|
play beep (60) for (0.2) seconds :: sound | Sound | One short, plain beep. Quick and simple — good for "done" or "ready". |
play beep (60) for (0.5) seconds :: sound | Sound | A musical tone at a pitch you choose, for a time you choose. Good for footsteps, tunes, splashes. |
play sound [Communication / Hello v] until done :: sound | Sound | A recorded clip picked from a list — words, animal noises, effects. Good for "voices". |
Which sound, when?
- Beep — a fast signal: "I started", "I finished".
- Note — when you want to choose the pitch and length: a tune or a rhythmic effect.
- Sound clip — when you want a real-world sound: a voice, a roar, applause.
Why it matters
A swimming Plesiosaurus can splash (a low note) as it paddles and call out (a sound clip) when it surfaces. Matching the sound type to the action makes the model tell a story.
Build & Program — the Plesiosaurus 17 min
Part A — Build
Build the Plesiosaurus. One Medium Motor drives both the legs and the paddle-like limbs, so it "swims" forward as it moves.
Components & ports: EV3 Brick · Medium Motor → port A.
- Build the long-necked body and attach the paddle limbs to a turning axle.
- Connect the Medium Motor to that axle through gears; plug it into port A.
- Check the paddles sweep as the legs move it forward.
- Turn the motor by hand to test one smooth paddle cycle.
Part B — Program
Splash with a low note on each paddle stroke, then call out with a sound clip at the end.
- Drag in the hat that starts the program:
when program starts :: events hat
- Set a steady paddling speed:
[A v] set speed to (50) % :: motors
- Play a low splash-note:
play beep (40) for (0.3) seconds :: sound
- Paddle forward one stroke:
[A v] run [clockwise v] for (1) [rotations v] :: motors
- Repeat the splash-note and stroke once more.
- Finish with a spoken sound clip:
play sound [Communication / Hello v] until done :: sound
when program starts :: events hat [A v] set speed to (50) % :: motors play beep (40) for (0.3) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play beep (40) for (0.3) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play sound [Communication / Hello v] until done :: sound
Expected behaviour: the Plesiosaurus splashes (low note) and paddles forward twice, then plays a spoken clip — three sound types working together.
Try It Yourself — three small builds 11 min
Goal: Swap the splash note for a plain beep on each stroke. Which feels more like water?
when program starts :: events hat play beep (60) for (0.2) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play beep (60) for (0.2) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors
Goal: A two-note splash — low then high — before each paddle stroke.
when program starts :: events hat play beep (40) for (0.2) seconds :: sound play beep (55) for (0.2) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play beep (40) for (0.2) seconds :: sound play beep (55) for (0.2) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors
Goal: Hafiz wants a full scene: a sound clip to "wake up", two splashing paddle strokes, then a clip to "dive".
when program starts :: events hat play sound [Communication / Hello v] until done :: sound play beep (40) for (0.3) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play beep (40) for (0.3) seconds :: sound [A v] run [clockwise v] for (1) [rotations v] :: motors play sound [Communication / Goodbye v] until done :: sound
Mini-Challenge — sound the scene 6 min
Combine all three sound types with the screen text from earlier. Show "SWIMMING" on the screen, splash with notes on each paddle stroke, and finish with a sound clip when the dino surfaces.
It works if:
- You use a beep or note for the strokes and a sound clip for the finish.
- The screen shows the action while it swims.
Recap 2 min
You compared the Brick's sounds. A short play beep (60) for (0.2) seconds is a quick signal, a longer play beep (60) for (0.5) seconds is a tone you shape, and play sound is a recorded clip. Match the sound to the moment.
- Sound clip
- A recorded sound (voice, effect) chosen from the Brick's list with play sound.
- Note vs beep
- A note lets you choose pitch and length; a beep is one fixed short sound.
Homework 1 min
Sound map. List one action for your model where a beep fits best, one where a note fits, and one where a clip fits.
Bring back next class: your three-line sound map.
Heads up for next class: EV3-L1-10 builds the T-Rex and puts motion and a roar together for a big finish.