21. Case 17: Alarm Device

21.1. Introduction

This is an alarm device. Press button A to make the red LED light on and flash, and the buzzer will be activated. Press button A again to cancel the alarm.

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21.2. Quick to Start

Materials

Nezha expansion board × 1

micro:bit × 1

LED-red × 1

RJ11 wires × 1

Bricks × n

Tips: You may need to purchase Nezha Inventor’s Kit if you want all the above compoents.

Connection Diagram

Connect the red LED to the J1 port on Nezha expansion board.

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Assembly Video

Video link:https://youtu.be/bYN6-6PskHQ

Assembly Steps

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21.3. MakeCode Programming

Step 1

Click “Advanced” in the MakeCode drawer to see more choices.

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We need to add a package for programming. Click “Extensions” in the bottom of the drawer and search with “PlanetX” in the dialogue box to download it.

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Note: If you met a tip indicating that the codebase will be deleted due to incompatibility, you may continue as the tips say or build a new project in the menu.

Step 2

Programme as the picture shows:

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Result

Press button A to alarm and the red LED flashes; press it again to stop the alarming and the LED turns off.

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