# 📡 Lesson Plan — IR Lab

> **Ages 10-13 · 40 min · 1 robot per pair · 1 IR remote per pair**

## 🎯 Objective
Students use an infrared remote to drive the robot, learn that **IR is invisible light carrying coded keys**, and discover how the floor line sensors (also IR) discriminate black vs. white.

## 🧰 Materials
- 1 Maqueen Lite v4 robot per pair (charged)
- 1 IR remote per pair (DFRobot or compatible NEC remote)
- 1 laptop/tablet per pair (Chrome or Edge)
- Black tape on white paper for line discrimination test
- Optional: phone camera (most can see IR LED purple flash)

## 📋 Lesson flow (40 min)

| Time | Phase | Teacher | Students |
|---|---|---|---|
| 0-5 | **Hook** | Show TV remote pointed at a phone camera — IR LED visible. "Light we can't see!" | Discuss visible vs. invisible spectrum. |
| 5-10 | **Demo** | Open IR Lab. Press a remote key — robot prints the key code. | Predict that each button has a unique number code. |
| 10-25 | **Exploration** | Pairs connect, map all 21 keys, then bind 4 keys to forward/back/left/right. | Build their own remote-control mapping. |
| 25-35 | **Challenge** | Show **line sensors** preview — robot outputs L=0/1 R=0/1 over black/white. "How could the robot follow a line on its own?" | Wave the robot over tape; predict; then discuss feedback loop. |
| 35-40 | **Reflection** | "Why does the remote work in sunlight but not always at the same range?" | Discuss IR competition with sunlight, line of sight. |

## ✅ Success criteria
- I can drive the robot with the remote using my own key bindings.
- I can predict the L/R sensor reading for any tape position.
- I can explain in one sentence how an IR remote sends a key.

## 📚 Standards
- **FR Cycle 3** — *Sciences* : lumière (visible/invisible) ; signal/information.
- **FR Cycle 4** — *Phys-Chim* : ondes électromagnétiques. *Tech* : codage de l'information.
- **NGSS** — MS-PS4-3 (digital signals more reliable than analog).
- **CSTA** — 1B-NI-04 (model how info travels); 2-NI-04 (network protocols).

## 🚀 Extension
- Bridge to the **Line Follower Race** game.
- Discuss why your TV remote needs line of sight.
- Build a 2-key code lock (key sequence unlocks a robot dance).