Lesson 3 - Temperature and Humidity Sensor: Temperature Monitor to Track Composting phase
1. Engage: Why Does Compost Get Hot?
Observe the picture below:
Key Question
Why does compost get warm?
When billions of tiny microbes break down carbon-rich scraps in compost (like dead leaves or banana peels), they release heat as they grow and multiply. This heat builds up, making the pile warm—sometimes even as hot as 65℃!
2. Explore: Effects of Temperature on Composting
Good temperature management can tell composters how fast material is decomposing, when compost is ready, and whether there are any problems.
Temperature is a compost super indicator:
Fast decomposition: Warm piles (30–60℃) mean microbes are super active, turning waste into plant food quickly.
Ready compost: When temps drop below 20℃, microbes have finished decomposing organic matter—your compost is ready to feed gardens!
Problem signs: Too hot (over 70℃) kills beneficial microbes; too cold means the pile is too dry, small, or lacks nutrients.
Moisture is just as vital: Microbes need water to digest food, like we need water to swallow! Too little moisture, and microbes slow down; too much, and the pile gets slimy (no oxygen can reach the microbes).
Key Question
How do we check temperature and moisture during the composting process?
Reveal: Today, we’ll use the UNIHIKER K10 and sensors to track compost temperature, monitor and manage our composting process.
Meet the Temperature & Humidity Sensor: Measures how hot or cold the compost is, and checks how much water is in the compost pile.
3. Engineer: Build Your Compost Monitor
Let’s set up our sensors to display real-time temperature on the UNIHIKER K10:
1.Make the hardware connections by the following diagram:
2.Go to the Coding tab and select Upload Mode.
3.Click Extension → Board → Download and install the UNIHIKER K10 and Building Block Expansion Board extensions.
4.Drag the following blocks together to build the code:
5.Upload the code to your UNIHIKER K10. Now you’ll see temperature reading on the UNIHIKER K10!
4.Experience & Challenge: Test & Track Your Monitor
Activity 1
Make hardware connection and write a program to display temperature.
Record the classroom’s baseline temperature.
Key Question
The data on the screen is flashing too quickly. Is there a way to display the temperature reading every 5 seconds?
Observe the code blocks below and discuss whether they can display a temperature reading every few seconds. How many seconds does it last?
The teacher uploads the program to demonstrate to the students, guiding them to observe that the numbers appear unchanged, making it impossible to tell that the temperature is being refreshed every 5 seconds.
Reveal: If the room temperature stays constant and the numbers hardly change, will this affect my recording every 5 seconds? How can I accurately record the temperature reading every 5 seconds?
Activity 2
Try the program below and explain what method is used to show you that the value refreshes every 5 seconds.
Place the Temperature & Humidity Sensor and a cup of hot water inside a sealed clear box.
Observe the UNIHIKER K10: What happens to the numbers?
Record the numbers in the table every 5 seconds.
Guide students to observe that the temperature is rising(Temperature rises as warm air fills the box!)
Research: Look up how compost temperature evolves over time (hint: it rises to high levels, then cools down when decomposition is done).
Students may draw a temperature line graph and paste it in the corresponding position on the background board.
5. Elaborate: Sensors for Land Conservation Beyond Compost
Temperature sensors are superheroes for protecting our planet’s land ecosystems:
Plant Growth: Track soil moisture to ensure garden or reforestation trees get just the right amount of water (no wasted water from overwatering!).
Wetland Protection: Monitor wetland humidity to preserve these critical habitats—they filter water and provide homes for frogs, birds, and insects.
Desert Restoration: Check soil moisture when planting drought-resistant plants, helping them survive and restore dry landscapes.
This work supports SDG 15: Life on Land—using tech to protect and restore our planet’s precious land ecosystems.
Key Takeaway: With simple sensors and code, we can be compost scientists and planet protectors, one data point at a time!
Lesson3(K10).zip 
