3. Case 02: Flower-watering Prompter

3.1. Introduction

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

../../_images/case_02_01.png

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

../../_images/Bricks_case_02.png

../../_images/case_02_02.png

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.

../../_images/case_02_03.png

Assembly


Build a device as the picture shows:

../../_images/case_02_04.png

../../_images/case_02_05.png

../../_images/case_02_06.png

../../_images/case_02_07.png

../../_images/case_02_08.png

../../_images/case_02_09.png

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.

../../_images/case_01_11.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.

Step 2

Code as below:

../../_images/case_02_10.png

Reference

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

You may also download it directly below:

---

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.