Page 168 - Toucpad robotics C11

21 st #Coding & Computational Thinking
project 3 Century # Experiential learning
Skills
The Automated Greenhouse System
Objective: Build a simplified, automated greenhouse system that can monitor environmental conditions
(temperature, humidity, soil moisture) and perform an action (e.g., turn on a water pump) based on the readings.
Steps of the Solution:
1. Project Planning & Design (Project Management):
Define the Scope: The system will monitor three parameters and control a single actuator.
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Component Selection:
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§ Brain: A microcontroller (like a Raspberry Pi Pico or an Arduino Uno) is ideal for this.
Senses: Choose a temperature sensor, a humidity sensor, and a soil moisture sensor.
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§ Muscles: A simple water pump and a relay module to switch the pump on and off.
§ Power: A suitable power adapter and an external power source for the pump.
Structure: A small, transparent container or a wooden frame can serve as the “greenhouse.”
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2. Hardware Assembly & Wiring:
Connect Sensors: Wire all three sensors to the microcontroller's analog and digital input pins.
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Connect Actuator: Connect the water pump to the relay module, and the relay module to a digital output
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pin on the microcontroller. The relay acts as a safety switch, allowing the microcontroller to control the
high-power pump with a low-power signal.
3. Programming & Control (Fundamentals, Logic, Systems):
Sensor Reading: Write code to read the values from each sensor. The soil moisture sensor will provide an analog
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reading, which will be converted to a digital number by the microcontroller's Analog-to-Digital Converter.
Decision-Making Algorithm: Use a combination of Boolean operators to create the control logic.
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Pseudocode:
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LOOP forever:
read soil_moisture_level
read temperature_level
read humidity_level
IF soil_moisture_level IS below_threshold AND temperature_level IS above_threshold
THEN turn_on_pump
ELSE
turn_off_pump
END IF
END LOOP
Time-Based Control: Use the microcontroller's timers to schedule sensor readings at regular intervals
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(e.g., every minute) to conserve power and avoid unnecessary checks.
4. Debugging & Testing (Ensuring Performance):
Unit Testing: Test each sensor to ensure it provides accurate readings. Test the relay module to ensure it
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can switch the pump on and off correctly.
System Testing: Place the system in the greenhouse and monitor its performance. Pour some water and
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check if the sensor reading changes. Allow the soil to dry out and verify that the pump turns on and waters
the plant automatically.
These projects will not only solidify a student's understanding of robotics but also demonstrate the practical
applications of the concepts we have covered, from the ground up.

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Touchpad Robotics - XI