Currently, we are in the final stages of Project Quest, our 6th grade interdisciplinary unit about the impact of water on civilization. I serve as one of the eight faculty members on the Quest team. During this unit, students work in groups to investigate some aspect of our relationship with water, driven by their own interest. The topic could cover the concept of water conservation, the Water Footprint, conflicts related to water usage, pollution or other area students might propose.
This year, one group studying the Water Footprint had the idea of building a type of LED bar graph that could represent different levels of water usage required for the production of various commodities. For example, one LED might represent 100 gallons, two LEDs represent 200 gallons, and so forth.
Arduino seemed like the ideal tool for this task, so this is what we chose to investigate. It turns out there is a simple bar graph sketch available from the Arduino website, using 10 LEDs and a potentiometer to set the various levels of light. While students at this grade level have not yet experienced the Arduino IDE, the sketch was simple enough to understand the basic underlying concepts. Working with me, they saw how a change in different values created different outcomes. For example, they only needed 8 LEDs in their project, so we had to adjust for that alteration in the code. Additionally, in the original code their dial (potentiometer) had to turn too much in order to light all LEDs, so they had to decrease the interval values between lights in order to get all eight to light up with a shorter turn of the dial. I also showed them how to use the Serial.print(); command to see the changing values coming from the potentiometer as they turned it.
The Project Quest exhibit day is coming up soon. The group is still working hard to finalize all aspects of their project. I know when the day comes, they will be ready to share what they have learned, not just about the Water Footprint, but a little coding as well.