🟦 Line Following Robot with mBlock

Here’s a simple and complete example project using mBlock (based on Scratch) for beginners. This project makes a robot follow a line using IR sensors—a common and fun way to learn robotics with mBlock!

🔧 Hardware Needed:

• mBot or mCore board
• 2 IR Line Follower Sensors (included in mBot)
• 2 Motors (left and right wheels)
• USB Cable or Bluetooth connection
• Power supply (batteries or USB)

🎯 Goal:

Make the robot detect and follow a black line on a white surface using mBlock (Scratch-based visual coding).

🧠 How it Works:

• The IR sensors detect the black line.
• If the left sensor sees black → turn left.
• If the right sensor sees black → turn right.
• If both sensors see white → go forward.

🧱 mBlock Code (Blocks):

✅ Step-by-step Code Blocks:

when green flag clicked
forever
    if (IR sensor left = black) and (IR sensor right = white)
        turn left (left motor slow, right motor fast)
    else if (IR sensor left = white) and (IR sensor right = black)
        turn right (left motor fast, right motor slow)
    else if (IR sensor left = black) and (IR sensor right = black)
        move forward (both motors fast)
    else
        stop (both motors stop)

📌 In mBlock (blocks):

when [Green Flag] clicked
forever
    if <(line follower port 2 value = 1)> and <(line follower port 3 value = 0)> then
        set motor M1 speed to 50
        set motor M2 speed to 100
    else if <(line follower port 2 value = 0)> and <(line follower port 3 value = 1)> then
        set motor M1 speed to 100
        set motor M2 speed to 50
    else if <(line follower port 2 value = 1)> and <(line follower port 3 value = 1)> then
        set motor M1 speed to 100
        set motor M2 speed to 100
    else
        stop motor M1
        stop motor M2

🖼️ Circuit Diagram:

The IR line follower module is usually connected to Port 2 on the mBot. Motors are connected internally.

✅ Tips:

• Place the robot on a black line with white background (e.g. electrical tape on paper).
• Adjust speed values if it’s turning too slow or too fast.

🧪 Experiment Ideas:

• Try making it follow curves.
• Add buzzer sound when it goes off the line.
• Display IR sensor values on the screen.