13. Case 12: The Burglar Alarm in Shops

13.1. Introduction

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• After installing the bulglar alarm device in shops, program to send alarms if someone breaks into the shops.

13.2. Function

• Detect the magnet from the magnetic(compass) function on the micro:bit, if the magnet goes far from the micro:bit, program to send alarms and light on the LED.

13.3. Products Link

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• 1 x microbit Smart City Kit Note: A piece of magnet requires in this project.

13.4. Picture

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13.5. Hardware Connection

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Connect the red led to P1 port on IoT:bit.

13.6. Software Program

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

For programming, we need to add a package: click “Extensions” at the bottom of the MakeCode drawer and search with “iot-environment-kit” in the dialogue box to download it.

Notice: If you met a tip indicating that some codebases would be deleted due to incompatibility, you may continue as the tips say or create a new project in the menu.

13.7. Program

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Detect the magnetic intensity in the current field, if the returned value is below the threhold, program to send alarms and flash on the led.

Link: https://makecode.microbit.org/_0fiexRbyoKpE

13.8. Result

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• If someone breaks into the shop, the device sends alarms and the led keeps flashing.