Lesson Plan

Courses

• Grades 3-12
• 3rd Grade – 12th Grade Courses

Materials

• Cellphone, tablet, or computer
• Internet connection

Description

In this activity, students can experiment in an introductory manner with Protobject, learning visual programming and computer science safely and playfully with a device.

Educational Objectives

• Understand the concepts of events and potentiometer.
• Create a technological object (prototype) using a device.
• Identify relationships between technology and the world around them.
• Evaluate their own work and that of others, individually or in teams.
• Engage in dialogue and reflection on improvement ideas.

Introduction (10 minutes)

Welcome students to the class and briefly introduce the day’s activity: “Today, we will learn how to prototype a lamp with variable intensity.”
We will start the class by providing students with the technical background necessary for the meaningful learning of the practical activity.
To kick off the class, we can start with a question:
Do you think colors appear the same on print as they do on a screen?

You can give students the floor to propose their answers and then complement with the correct answer.
Subtractive synthesis and additive synthesis are two different ways of mixing colors and creating new ones.
Subtractive synthesis is primarily used in paper printing, such as books, newspapers, magazines, etc. When we look at a colored object, we are actually seeing the color it reflects and absorbs. For example, if we see a red object, it means it is absorbing all colors except red, which it reflects.
In subtractive synthesis, we start with a white light source (containing all colors) and use colored inks or pigments to absorb some of the colors and reflect others. So, if we mix different colored inks, the amount of reflected light decreases, and the perceived color changes. Mixing all color inks (cyan, magenta, yellow) together, they absorb almost all colors and reflect only a little light, resulting in black.
On the other hand, additive synthesis is used in creating images on electronic screens, like TVs, computers, and mobile phones. In this case, the light source comes from the screen’s pixels and adds up to create colors. If we add all colors together (red, green, and blue), we get white light.
In additive synthesis, different shades of gray can be created by mixing different amounts of light from the primary colors: red, green, and blue. If we want to create a darker gray, we can reduce the intensity of the primary colors on the screen, reducing the total amount of emitted light and resulting in a darker gray. Conversely, if we want to create a lighter gray, we can increase the intensity of the primary colors, increasing the total amount of emitted light, resulting in a lighter gray.
Black corresponds to the absence of light and is achieved by turning off all primary colors (red, green, and blue). On the other hand, white is achieved by adding the maximum amount of light from the primary colors, which means all primary colors are at their maximum.
So, we can create different shades and hues of colors and grays on a screen by manipulating the quantity and intensity of light emitted by the primary colors.
Do you remember what a potentiometer is?
You can give students the opportunity to propose their answers, and then complement with the correct answer.
A potentiometer is a component, usually with a knob, used in electronic circuits to control the amount of electricity flowing through a wire. A potentiometer can be used, for example, to adjust the volume of a radio, or even, you can adjust how much electricity reaches the pixels of the primary colors on the screen to make them darker or lighter!
In this case, by turning the potentiometer to one side, the screen will display a darker gray, all the way to black, and by moving it to the other side, it will display a lighter gray, all the way to white.
With Protobject, we can simulate a potentiometer on the smartphone screen so we can use it to control the amount of emitted light to create different shades of gray.
Finally, to kickstart the prototyping process and make them feel like the protagonists of their learning, ask them:
Do you want to learn how to prototype a lamp with variable intensity?

Development (20-30 minutes)

We connect our device to the Protobject platform. For this exercise, we will use LAMP and SIMPLEKNOB.
Remember to experiment beforehand by yourself before asking the students to experiment with Protobject so that you can anticipate questions that may arise from the students.
First, we will activate the knob with the SIMPLEKNOB block to tell it what to do when the knob changes.
Now, we will tell it what to do with the LAMP turn-on block, assigning the colors red, green, and blue and having them change when the knob is turned.
Since they all change in the same proportion, we will obtain different shades of gray.
To test the prototype, we will instruct the students to click on the activation button.
Congratulations!

Closure (5-10 minutes)

Now that you have prototyped a lamp with variable intensity using Protobject, introduce the next topic to your students with a question:

• How would you adjust the intensity of a red, green, or blue light?

To solve the challenge presented, it is necessary to add a conditional and evaluate the knob’s rotation with each event. If it exceeds 80, music will play. Otherwise, it should be turned off. If this is not done, the music will never stop!
Check the challenge solution.