13. Case 12: The Burglar Alarm in Shops#

13.1. Introduction#

  • 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.

13.4. Picture#

../../_images/microbit-Smart-City-Kit-case-01-02.png

13.5. Hardware Connection#

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

../../_images/microbit-Smart-City-Kit-case-12-03.png

13.6. Software Program#

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

../../_images/microbit-Smart-City-Kit-case-01-04.png

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.

../../_images/microbit-Smart-City-Kit-case-01-05.png

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#

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.

../../_images/microbit-Smart-City-Kit-case-12-07.png

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

13.8. Result#

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