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Drought in Africa – Smart Irrigation System for TI-84 Plus CE OS 5.3

Drought in Africa – Smart Irrigation System for TI-84 Plus CE OS 5.3

Author: Texas Instruments Inc.

Argomento:  Biology, Computer Science, STEM

Tags:  Biology, Coding, Programming, Sine, STEM

This is an integrated STEM project that challenges students to build an irrigation system. Students will learn and use concepts in computer science, environmental science and engineering.

Build a Solution

In this project, students are challenged to use science and technology to design and build a system that utilizes a limited amount of water in a “smart” way to grow crops. To achieve this, they need STEM skills and knowledge from the disciplines of ecology, biology, chemistry, electronics, logic and computer programming. To enable students to complete this project, they are challenged to complete smaller tasks that will provide the programming and electronics knowledge required. In addition, during the project, the teacher has the opportunity to teach scientific principles in a relevant and meaningful setting. Some of the following science principles could be worked into the activity.

  • The effect of temperature on the evaporation rate of water? Should water be used when it is hot or cool?
  • How does soil type affect the percolation of water into the ground? Should water be delivered in a strong rush? Or should it be delivered slowly and in pulses?
  • Does relative humidity affect the evaporation rate of water? Does warm air hold more water than cool air? What is relative humidity? Should water be delivered when relative humidity is high or low?


This project assumes the students have a working knowledge of the programming concepts in the Digital Mood Ring project. Please refer to that project as a review of concepts*. In smart irrigation project, students are challenged to build and program a smart irrigation system based on the engineering concept of a feedback and control loop. The system uses three input modules; a temperature-humidity sensor, a soil moisture sensor, and an ambient light level sensor. The system has a single output to a power control unit with a water pump connected. A program is written to read all four input parameters and logically compare them with critical set-point values and among each other to determine when to turn the water pump on and off. The project is presented in a series of small challenges that build the knowledge and skills required for the final open-ended challenge. The final challenge also relies on the students’ understanding of important biology and ecology topics that are relevant to optimizing the system the students ultimately design and refine. 

Contact STEM-team@ti.com with questions about the project.

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