7. case 05 Water Level Alarming


7.1. Goal

  • Make a water level alarming.

7.2. Materials

  • 1 x Smart home Kit]

  • 1 x tank

7.3. Background

What is water level alarming

  • We can’t live without water, but much water will cause flood. Water level alarming can detect water level, micro:bit will received signals when the water level over security line and control lift pump to pumping.

Water level alarming operation

  • When micro:bit received signal of soil moisture sensor,relay will drive and supply power to lift pump for pumping redundant water.


7.4. Practical operation

Preparing a tank and paste devices as below piture:


7.5. Hardware connect


7.6. Software


Edge Connector Data Sheet

7.7. Programming

Step 1

Go to MakeCode page, click Advanced in the code block and click on Extensions.


We need to add a new codebase for programming of smart home. Finding “Add Package” in the bottom of code block and click it. Then a message box will show up, search “smart home”, and download this new codebase.


Note:If there is a hint says some codebase will be deleted because of incompatibility. Don’t worry. You could go ahead as the hint or build a new item in item menu bar.

Step 2

Snap if statement into forever,set analog read pin P2 > 500, that’s say when P2 > 500, the water level is higher than security line.


Step 3

Set start melody “ba ding” repeating once as alarming voice, set digital write pin P1 to 1 as driving the pumping.


Step 4

Else,set digital write pin P1 to 0 as turning off the pump.



Make code:https://makecode.microbit.org/_9KqHhp1J45ho

You also could directly download program visit website as below:


7.8. Result

When the water level over security line,micro:bit will control lift pump to pumping.



Stop pumping:


7.9. Think

How to use micro:bit control water level in fish tank ?

7.10. Questions

7.11. More information