RGB LED color mixing in Raspberry Pi - Step-by-Step Execution

Concept Flow - RGB LED color mixing

Start

↓

Set Red Intensity

↓

Set Green Intensity

↓

Set Blue Intensity

↓

Combine Colors

↓

Output Mixed Color to LED

↓

End

The program sets the intensity of red, green, and blue LEDs, combines them, and outputs the mixed color to the RGB LED.

Execution Sample

Raspberry Pi

red = 255
green = 100
blue = 50
color = (red, green, blue)
print(color)

This code sets red, green, and blue values, combines them into a color tuple, and prints the result.

Execution Table

Step	Variable	Value	Action	Output
1	red	255	Set red intensity to max
2	green	100	Set green intensity to medium
3	blue	50	Set blue intensity to low
4	color	(255, 100, 50)	Combine RGB values into tuple
5	print(color)		Output the combined color	(255, 100, 50)
6	-	-	End of program

💡 All RGB values set and combined; program ends after printing the color tuple.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
red	undefined	255	255	255	255	255
green	undefined	undefined	100	100	100	100
blue	undefined	undefined	undefined	50	50	50
color	undefined	undefined	undefined	undefined	(255, 100, 50)	(255, 100, 50)

Key Moments - 3 Insights

Why do we combine red, green, and blue values into a tuple?

Combining into a tuple groups the three color intensities so they can be sent together to the LED, as shown in step 4 of the execution_table.

What does the printed output (255, 100, 50) represent?

It represents the combined color intensities for red, green, and blue channels that the LED will display, as seen in step 5 of the execution_table.

Why do the variables red, green, and blue have values before color is set?

Because color depends on red, green, and blue values, they must be set first (steps 1-3) before combining them in step 4.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of 'green' after step 2?

A 100

B 255

C 50

D undefined

💡 Hint

Check the 'Value' column for 'green' at step 2 in the execution_table.

At which step is the RGB color tuple created?

A Step 2

B Step 4

C Step 5

D Step 3

💡 Hint

Look for the action 'Combine RGB values into tuple' in the execution_table.

If we change blue from 50 to 200, what will be the new color tuple at step 4?

A (255, 100, 50)

B (255, 200, 50)

C (255, 100, 200)

D (200, 100, 50)

💡 Hint

The tuple is (red, green, blue). Changing blue affects the third value, see variable_tracker.

Concept Snapshot

RGB LED color mixing:
- Set red, green, blue intensities (0-255)
- Combine as (red, green, blue) tuple
- Send tuple to LED to mix colors
- Higher value = brighter color
- Mix creates many colors by blending intensities

Full Transcript

This example shows how to mix colors on an RGB LED by setting red, green, and blue values. Each color is set from 0 to 255, where 0 means off and 255 means full brightness. We combine these three values into a tuple representing the mixed color. The program prints this tuple to show the final color sent to the LED. The execution table traces each step: setting red to 255, green to 100, blue to 50, combining them, and printing the result. The variable tracker shows how each variable changes step by step. Key moments clarify why we combine colors and what the output means. The quiz tests understanding of variable values and tuple creation. This helps beginners see how RGB mixing works in code on a Raspberry Pi.