3. Case 02: Flower-watering Prompter

3.1. Introduction

To make a flower-watering prompter with a micro:bit.

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3.2. Quick Start

Materials Required

Nezha expansion board × 1

micro:bit × 1

LED-red × 1

LED-green × 1

Soil moisture sensor × 1

RJ11 wires × 3

Bricks details

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Connection Diagram

  • Connect the green LED to J4, red LED to J3 and soil moisture sensor to J2 on the Nezha expansion board as the picture shows.

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Assembly

Build a device as the picture shows:

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Video reference:https://youtu.be/YxEKEoDB6FQ

3.3. MakeCode Programming

Step 1

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

../../_images/case_01_10.png

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

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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.

Step 2

Code as below:

../../_images/case_02_10.png

Reference

Link：https://makecode.microbit.org/_2FgMYuLiUeE8

You may also download it directly below:

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Result

  • The red LED lights on for reminding of watering if the soil moisture sensors gets a low value from the earth, or the green LED lights on.