Studio build: two sprites that cooperate
Ākonga use broadcast messages so one sprite triggers another, and draw the message flow before wiring it, so the coordination is designed rather than discovered.
- Coding Studio move: Message-flow sketch, then the working multi-sprite build
- Evidence it produces: A project where a named broadcast reliably starts a second sprite's behaviour
Lesson 6: Broadcasting Messages & Multi-Sprite Event Coordination
Developing computational thinking through Scratch block coding, algorithms, and Te Ao Māori perspectives.
🎯 Ngā Whāinga Akoranga | Learning Intentions
Broadcasting as an event-driven signal mechanism allowing different sprites to communicate, trigger scene changes, and synchronize actions.
Send and receive broadcast messages ('broadcast [game over]', 'when I receive [start game]'), coordinate multi-sprite conversations, and switch backdrop scenes.
🎥 Media Anchor & Pedagogical Scaffold
Scratch — Events: Broadcast Command & Coordinating Actions
Video Clip: Explains how event programming works in Scratch — one part of a program waits for a signal from another. Covers broadcast and receive blocks for coordinating multiple sprites.
🧠 1. Before Viewing (Activate & Predict)
How do multiple sprites in Scratch know when it is their turn to speak or act without interrupting each other?
👁️ 2. During Viewing (Watch With a Job)
- Watch the full clip. Identify the two blocks that work as a pair: "broadcast [message]" and "when I receive [message]" — which sprite sends, and which receives?
- Think about the difference between using a "wait 2 seconds" block versus a broadcast — why is the broadcast approach more reliable for timing?
- After watching, add a broadcast to your project so that one sprite triggers an action in a second sprite — for example, a scene change or a response.
🗣️ 3. After Viewing & Kaiako Move (Process & Apply)
Kaiako Move: Demonstrate building a multi-scene animated pūrākau (e.g. Māui slowing the sun) using broadcast messages for scene changes.
Immediate Task: Complete Section 6 of your Digital Tech Logbook: Broadcast Communication Map & Multi-Scene Script.
⚡ Whakaoho | Do Now: The Director and the Stage Crew (10 mins)
In pairs: one of you is the director, one the stage crew. The director holds up cards that say "Scene 1" and "Scene 2"; the crew changes the paper backdrop each time a card goes up. That card is a broadcast — one message, many listeners. Today the sprites get the same system.
📖 Activity 1: Two Scenes, One Message — Broadcast in Action (25 mins)
Build the two-scene pūrākau starter with the projector: broadcast [scene-1] from the stage, and when I receive [scene-1] scripts on the sprites that switch backdrops and show or hide characters. Add scene 2 with its own backdrop and a new sprite entrance, sending and receiving exactly the message names you chose. Then plan scene 3 on paper first — which sprites hide, which listen, what the message is called — before you build it. House rule: message names must describe the scene, never "message1".
📝 Activity 2: Digital Tech Logbook & Code Reflection (20 mins)
Draft your formal Digital Tech Logbook entry for Lesson 6. Apply exact programming vocabulary (e.g., broadcast, when I receive, message, scene, event, coordinate) to explain your code decisions.
🏫 Kaiako Planning & Pedagogy Notes
Year 7 Curriculum Alignment: Broadcasting and multi-sprite coordination (NZC Technology; Te Mātaiaho Phase 3) — one message, many listeners: the coordination Lesson 8's scenes need.