Line following with camera in Drone Programming - Mini Project: Build & Apply

Line following with camera

📖 Scenario: You are programming a small drone to follow a black line on the ground using its camera. The drone's camera captures images, and you will process these images to detect the line and control the drone's movement to stay on the line.

🎯 Goal: Build a simple program that processes camera image data to detect a black line and outputs the drone's movement commands to follow the line.

📋 What You'll Learn

Create a list representing a camera image row with pixel brightness values

Set a threshold value to detect dark pixels representing the line

Use a loop to find the position of the line in the image row

Print the drone's movement command based on the line position

💡 Why This Matters

🌍 Real World

Drones use cameras to follow lines or paths on the ground for tasks like delivery or inspection.

💼 Career

Understanding how to process camera data and control drones is useful for robotics and autonomous vehicle jobs.

1

Create camera image data

Create a list called camera_row with these exact pixel brightness values: [255, 255, 0, 0, 0, 255, 255]. These values represent a row of pixels from the drone's camera, where 0 means black and 255 means white.

Drone Programming

# Create the camera_row list with pixel brightness values
# Your code here

Need a hint?

Think of the camera row as a list of numbers showing how bright each pixel is. Black pixels have value 0.

2

Set threshold for line detection

Create a variable called threshold and set it to 50. This threshold will help detect dark pixels representing the line.

Drone Programming

camera_row = [255, 255, 0, 0, 0, 255, 255]
# Set the threshold value to detect dark pixels
# Your code here

Need a hint?

The threshold is a number to decide if a pixel is dark enough to be part of the line.

3

Find line position in camera row

Use a for loop with variable index to go through camera_row. Find the first pixel where the brightness is less than threshold. Save this index in a variable called line_position. If no pixel is dark, set line_position to -1.

Drone Programming

camera_row = [255, 255, 0, 0, 0, 255, 255]
threshold = 50
# Use a for loop to find the first dark pixel and save its index as line_position
# Your code here

Need a hint?

Loop over each pixel index and check if the pixel is dark. Stop when you find the first dark pixel.

4

Print drone movement command

Write a print statement to display the drone's movement command based on line_position. If line_position is -1, print "No line detected: Hover". If line_position is less than 3, print "Turn left". If line_position is greater than 3, print "Turn right". Otherwise, print "Go straight".

Drone Programming

camera_row = [255, 255, 0, 0, 0, 255, 255]
threshold = 50
line_position = -1
for index in range(len(camera_row)):
    if camera_row[index] < threshold:
        line_position = index
        break
# Print the drone movement command based on line_position
# Your code here

Need a hint?

Use if-elif-else to decide the command based on where the line is detected.