Logic

Programs don't just calculate.

They also need to make decisions.

Questions like:

Is the button pressed?
Is the temperature too high?
Is the distance less than 10 cm?
Did the player score enough points?

The Logic category allows programs to ask questions and decide what to do next.

Think of Logic as the decision-maker inside your robot.

What Is Logic?

Logic blocks ask questions.

Every question has one of two answers:

TRUE

FALSE

Example:

5 > 3

↓

TRUE

2 > 10

↓

FALSE

Think of Logic as the brain of your program.

Logic Category

[INSERT CATEGORY IMAGE HERE: Logic]

Figure 3.1 – Blocks available in the Logic category.

The Logic category can be organized into:

COMPARE

↓

COMBINE

↓

REVERSE

↓

DECIDE

Logic Block Quick Reference

Block	Purpose	Main Idea
Comparison	Compare values	Ask a question
Range Check	Check limits	Between values
AND	Both conditions	All must be true
OR	Either condition	One can be true
NOT	Reverse result	Opposite answer
TRUE/FALSE	Boolean values	Yes or No
If True / If False	Choose a value	Decision making
In / Not In	Check a list	Exists or not
To Boolean	Convert to TRUE/FALSE	Logical value

Comparing Values

[INSERT BLOCK IMAGE HERE: Comparison]

Comparison blocks ask questions.

Comparison Options

Question	Meaning
=	Equal to
≠	Not equal
<	Less than
≤	Less than or equal
>	Greater than
≥	Greater than or equal

Examples

5 = 5

↓

TRUE

5 ≠ 5

↓

FALSE

10 > 3

↓

TRUE

Concept

Question

↓

TRUE/FALSE

Comparing Sensor Values

A sensor reading can be compared to a limit.

Example:

Temperature > 30

Result:

TRUE

FALSE

Concept

Sensor

↓

Compare

↓

Result

Range Checks

[INSERT BLOCK IMAGE HERE: Range Comparison]

Sometimes a value must stay between two limits.

Example:

0 < Score < 100

This asks:

Is the score between 0 and 100?

Concept

Lower Limit

↓

Value

↓

Upper Limit

TRUE and FALSE

[INSERT BLOCK IMAGE HERE: Boolean]

The most important Logic values are:

TRUE

and

FALSE

Think of Them As

TRUE = YES

FALSE = NO

Combining Conditions

[INSERT BLOCK IMAGE HERE: AND/OR]

Sometimes one question is not enough.

AND

AND requires both conditions to be true.

Example:

Button Pressed

AND

Distance < 10

Result:

TRUE

only if both are true.

Memory Tip

AND = BOTH

OR

OR requires only one condition to be true.

Example:

Button Pressed

Remote Button Pressed

Memory Tip

OR = EITHER

AND vs OR

Block	Meaning
AND	Both conditions
OR	One or both conditions

Example

Rain

AND

Wind

↓

Need both

Rain

Wind

↓

Need only one

NOT

[INSERT BLOCK IMAGE HERE: NOT]

NOT reverses the answer.

Examples

TRUE

↓

NOT

↓

FALSE

↓

NOT

↓

TRUE

Memory Tip

NOT = OPPOSITE

Choosing Between Two Values

[INSERT BLOCK IMAGE HERE: If True / If False]

Sometimes we want one value if something is true and another value if it is false.

Example:

IF Temperature > 30

↓

HOT

ELSE

↓

Concept

Question

↓

TRUE?

↙ ↘

Yes No

↓ ↓

Value A Value B

Checking a List

[INSERT BLOCK IMAGE HERE: In]

Logic can check if a value exists inside a list.

Example:

3 in [1,2,3,4]

↓

TRUE

8 in [1,2,3,4]

↓

FALSE

Converting to Boolean

[INSERT BLOCK IMAGE HERE: To Boolean]

This block converts a value into:

TRUE

FALSE

Concept

Value

↓

Boolean

↓

TRUE/FALSE

Logic and Control

Logic and Control work together.

Logic asks the question.

Control decides what to do.

Example:

Distance < 10

↓

TRUE

↓

Turn LED ON

Concept

QUESTION

↓

TRUE/FALSE

↓

ACTION

Logic and Sensors

Logic becomes most useful when used with sensors.

Example:

DHT11

↓

Temperature

↓

Compare

↓

Decision

Temperature Alarm

Temperature > 30

↓

TRUE

↓

Turn Buzzer ON

Obstacle Detector

Distance < 10

↓

TRUE

↓

Stop Robot

Temperature Warning System

Temperature

↓

> 30?

↓

TRUE

↓

LED ON

Skills:

Comparison

Sensors

Decisions

Obstacle Detector

Distance

↓

< 10?

↓

TRUE

↓

Buzzer

Skills:

Ultrasonic Sensor

Logic

Outputs

Score Checker

Score

↓

>= 10?

↓

TRUE

↓

Winner!

Skills:

Variables

Comparisons

Control

Quick Guide for Students

Need to compare values?

Use:

=  ≠  <  >  ≤  ≥

Need both conditions?

Use:

AND

Need only one condition?

Use:

Need the opposite answer?

Use:

NOT

Need TRUE or FALSE?

Use:

Boolean

Need to check limits?

Use:

Range Comparison

Quick Reference

Family	Main Idea
Comparison	Ask a question
Range	Check limits
AND	Both conditions
OR	Either condition
NOT	Opposite result
Boolean	TRUE/FALSE
Conditional Value	Choose between values
Membership	Check a list
Boolean Conversion	Convert to TRUE/FALSE

Summary

In this lesson, you learned how Logic helps programs make decisions.

You explored:

Comparisons

TRUE and FALSE

AND

NOT

Range Checks

Conditional Values

Membership Tests

Sensor Decisions

Logic helps programs decide what to do based on information they receive from sensors, variables, and user input.

Key Takeaway

Logic is the decision-maker inside your program. It asks questions, produces TRUE or FALSE answers, and helps your robot decide what action to take next.