Microbit Plant Watering Reminder: Fun coding Activity (2026)

Automatic Plant Watering Reminder using BBC Micro:bit : Overview

The Automatic Plant Watering Reminder is a beginner-friendly STEM project using the BBC Micro:bit to remind users when plants need watering. It introduces timers, variables, LEDs, and programming while encouraging plant care. Instead of controlling a pump, the Micro:bit provides visual and sound reminders that can later be expanded into a smart irrigation system. Students gain practical experience with embedded systems and discover how technology can solve everyday problems. This project is suitable for classrooms and home learning.

Innovation

The Plant Watering Reminder is programmable, reusable, and easy to customize for different plants.

Materials Required for Automatic Plant Watering Reminder

BBC Micro:bit
USB cable
Computer with MakeCode

Learning Objectives

Learn variables, loops, timers, LED output, and event-based programming through this Automatic Plant Watering Reminder.

Procedure

Connect the Micro:bit, create a MakeCode project, initialize variables, create a repeating timer, check reminder intervals, display LED icons, play a sound, and reset after acknowledgement.

Detailed Block-Based Coding Logic

Step 1: Create a New Project

Open Microsoft MakeCode and click New Project. Name your project Automatic Plant Watering Reminder.

This creates a workspace where you can build the program using drag-and-drop coding blocks.

Purpose

• Starts a new Micro:bit project. 
• Organizes all coding blocks in one workspace. 

Step 2: Add the On Start Block

The On Start block runs only once when the Micro:bit is switched on or reset.

Inside this block, create a variable called Days and set it to 0.

On Start

    Set Days = 0

Explanation

The variable Days stores how many reminder cycles have passed.

Every program begins with the value set to zero so the reminder starts fresh.

Concepts Learned

• Variables 
• Initialization 

Step 3: Display a Welcome Icon

Still inside the On Start block, add:

Show Icon (Happy)

Explanation

When the Micro:bit starts, it displays a smiling face to show that the watering reminder is active.

This gives users immediate feedback that the program has started correctly.

Step 4: Add the Forever Block

Drag the Forever block into the workspace.

Everything inside this block repeats continuously while the Micro:bit is powered.

Forever

Explanation

Plants need watering reminders repeatedly.

Therefore, the program must continuously check whether it’s time to remind the user.

Concept Learned

• Infinite Loop 

Step 5: Wait for a Time Interval

Inside the Forever block, add

Pause (10000 ms)

(For classroom demonstrations. In a real project this can represent a much longer interval.)

Explanation

The pause block tells the Micro:bit to wait before checking again.

Without a pause, the program would repeat thousands of times every second.

Concept Learned

• Timing 
• Delays 

Step 6: Increase the Counter

After the pause block, add

Change Days by 1

Explanation

Every time the waiting period finishes, the variable Days increases by one.

For example

This variable acts as the reminder timer.

Step 7: Check the Reminder Condition

Add an If block.

If Days ≥ 3

(Use any reminder value you prefer.)

Explanation

The program compares the current value of Days with the reminder limit.

If the value reaches three, the Micro:bit knows it is time to water the plant.

Concept Learned

• Conditional Statements 
• Decision Making 

Step 8: Display a Watering Reminder

Inside the If block add

Show LEDs

Create a simple watering-can or water-drop pattern on the 5 × 5 LED display.

Then add

Show String

“WATER”

Explanation

The LED pattern immediately catches attention.

The scrolling message clearly reminds the user what action to take.

Step 9: Play a Melody

Still inside the If block add

Play Melody

Power Up

or

Play Tone

Explanation

The sound alert ensures the reminder can be noticed even when the user is not looking directly at the Micro:bit.

Using both light and sound makes the reminder more effective.

Concept Learned

• Output Devices 
• Audio Feedback 

Step 10: Reset the Reminder

Add

If Button A is Pressed

Set Days = 0

Show Icon (Happy)

Explanation

After watering the plant, the user presses Button A.

The counter resets to zero and the Micro:bit begins counting again for the next reminder cycle.

This creates a reusable watering reminder instead of a one-time alert.

Applications

Home gardening, school STEM lessons, smart farming awareness, indoor plants, and IoT learning.

Conclusion

This Plant Watering Reminder project helps students combine programming with environmental responsibility and provides a foundation for future smart gardening projects.

FAQs

1. What is the purpose of the Automatic Plant Watering Reminder?
   The Plant Watering Reminder project reminds users when it is time to water their plants using the BBC Micro:bit’s LED display and sound alerts. It helps students learn programming while encouraging regular plant care.
2. Does this project water the plants automatically?
   No. This version only provides reminders. It can be upgraded by adding a soil moisture sensor, relay module, and water pump to create an automatic watering system.
3. Why is a variable used in this project?
   A variable stores the reminder counter or elapsed time. The Micro:bit checks this value continuously to determine when to display the watering reminder.
4. Why is the Forever block important?
   The Forever block continuously runs the program, allowing the Micro:bit to monitor the reminder timer and trigger alerts at the correct interval.
5. Can I change the reminder interval?
   Yes. You can modify the pause duration or the target value of the counter variable in MakeCode to remind you every few hours, every day, or at any custom interval.