We Need More LEDs!

We have had a busy start to the new year for the 4th and 5th graders in the STEM lab. Between half weeks, holidays, early dismissals, rain delays, and 5th graders going to camp; we have had to make some adjustments. However, we have persevered and filled our time with flashing lights and 3D design.

This unit has a two part focus, electric circuits and 3 dimensional design and printing. My goals for the electricity portion were to give the students more hands-on practice building circuits and to teach them to use bread boards and LEDs as a lead in to the physical computing unit coming up in the 4th nine weeks. As for the 3D design/printing, these classes have spent the year so far engineering and building with their hands in the physical world and I wanted them to have some exposure to designing objects in the digital realm.

We began our work on circuits by reviewing what students already knew about the topic. The students are all well versed in the vocabulary of electrical circuits, conductor, insulator, open and closed circuits, switches, and so on. We discussed the various components that we would be using and how they fit into the students' existing knowledge. New terms included resistor and breadboard. Most had heard of an LED but were not familiar with what it stands for, light emitting diode. We examined the breadboard and sketched out how the different sets of holes are connected. Then I talked the students step by step through setting up a complete circuit. The best part of this unit so far has been the loud "oohs" and "aahs" that have accompanied the moment that first LED begins to glow. From there students build circuits using the remaining LEDs and resistors. In the next lesson, students are introduced to adding a button that turns their lights on when it is pressed. This exercise provides a great teachable moment in debugging circuits because there is always a group or two that wires the button in such a way that it turns the lights off by creating a short circuit when it is pressed. Once the students master the button, I have them add a buzzer. (Truth be told, these buzzers are much louder than I thought they would be when I ordered them.) The final challenge is then to connect all 5 LEDs and the buzzer to the button. Because of the small size of the breadboards we are using, the students must figure out how to use both halves of it in order to connect all of the components.

The materials for this part of the unit were provided by the generous individuals who supported my Donors Choose grant earlier this year. I cannot thank them enough.

The other half of this unit centers on the principles of 3D design and 3D printing. Students use a series of lessons provided by Project Ignite to learn hoe to use the tools in Tinkercad. This elementary computer assisted design program allows students create 3 dimensional objects digitally. These can then be printed on the classroom 3D printer. Students must complete the lessons and demonstrate mastery of the vocabulary and tools before being allowed to design and print an original object. One issue that keeps cropping up is that students get distracted designing some truly amazing things mid lesson and lose track of what they are supposed to be doing. (I suppose they are staying true to the spirit of tinkering.) A number of students have been able to print so far, and many more have completed the lessons and will be able to design and print during the next rotation. Moving forward, this year and into next, I will have students design and print objects not for their own sake, but as parts of other projects.