dr. gary stewardson, raymond boyles hello again, sparkey here. slippery and i will help you explore...

Dr. Gary Stewardson, Raymond Boyles

Hello again, Sparkey here. Slippery and I will help you explore how to create a program that simulates outputs on a traffic light. Make sure you have your guided notes.

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Flowcharts

Dr. Gary Stewardson, Raymond Boyles

Flowcharts can be a useful tool that better enable us to organize, problem solve, and brainstorm when we are writing a program. Flowcharts are similar to thinking maps and concept maps we use to organize, problem solve, and brainstorm when we are writing a paper.

Flowcharts

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Dr. Gary Stewardson, Raymond Boyles

In our last program, we wrote a program to turn on a light for two seconds. Let’s use symbols to represent the logical flow of this program.

Flowcharts

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Dr. Gary Stewardson, Raymond Boyles

Symbols

Start and Stop symbols represent the beginning or end of a program. These symbols are simply a place holder and are oval.

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Dr. Gary Stewardson, Raymond Boyles

Input and outputs from the computer can be represented by the parallelogram symbol below. We use this symbol to represent when we turned the light on.

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Symbols

Dr. Gary Stewardson, Raymond Boyles

Symbols

We can also use this symbol to represent a switch or a touch sensor.

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Dr. Gary Stewardson, Raymond Boyles

Symbols

Process symbols represent computational action as rectangles or blocks and represent “Action”. For example, we use this symbol to represent the timer counting two seconds.

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Dr. Gary Stewardson, Raymond Boyles

Symbols

The decision symbol represents a yes/no and is in the shape of a diamond. We use this symbols to represent testing if the counter has counted to two.

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Dr. Gary Stewardson, Raymond Boyles

Symbols

The decision symbol can also represent if a switch or a touch sensor is pushed or not.

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Dr. Gary Stewardson, Raymond Boyles

Symbols

The arrow symbols represent the direction of flow in a program. The arrow symbols shows how the logic flows in a computer program.

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Dr. Gary Stewardson, Raymond Boyles

Complete Flowchart

The connection of all the symbols shows a process. The flowchart to the right represents the process of turning a light on for two seconds, then turning off the light, and then ending the program.

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Dr. Gary Stewardson, Raymond Boyles

Complete Flowchart

1. Start the process

2. Turn on the light

3. - If (Yes) the time has expired then: Go to Stop- If (No) the time has not expired then keep counting

4. Turn off the light

5. Stop

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Dr. Gary Stewardson, Raymond Boyles

Flow Chart Activity

Our next program will perform the following so please write these down in your activity guided notes:

• The green light and red light will turn on for two seconds.

• The green and red light will turn off.

• The green and yellow light will turn on for one second

• The green and yellow light will turn off 13

Dr. Gary Stewardson, Raymond Boyles

Flow Chart Activity

Wiring:

• The green light is connected to Port A of the NXT controller and relay 1 on the relay board.

• The yellow light is connected to Port B of the NXT controller and relay 2 on the relay board

• The red light is connected to Port C of the NXT controller and relay 3 on the relay board

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Dr. Gary Stewardson, Raymond Boyles

Pre-Programming Activity

With the symbols below and the PowerPoint guided notes, create a flow chart that represents a computer program that will logically follow the steps you have just written in your Activity 10 guided notes.

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Dr. Gary Stewardson, Raymond Boyles

Flow Chart

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Your flow chart should look something like the flowchart pictured to the right.

Dr. Gary Stewardson, Raymond Boyles

Flow Chart

NXT Object Reference

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Your computer program should look something like the flowchart pictured to the right.

Dr. Gary Stewardson, Raymond Boyles

Complete Flowchart

Can you flowchart the process of a traffic light?

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Dr. Gary Stewardson, Raymond Boyles

Complete Flowchart

Now, let us complete Activity 10

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