Goal
- Make a water level alarming.
Materials
- 1 x Smart home Kit
- 1 x tank
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.
Practical operation
Preparing a tank and paste devices as below piture:
Hardware connect
Software
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.
Programming
Make code：https://makecode.microbit.org/_1XpJDo2Y0aDL
You also could directly download program visit website as below:
Result
When the water level over security line,micro:bit will control lift pump to pumping.
Pumping:
Stop pumping:
Think
How to use micro:bit control water level in fish tank ?