The goal of this project is to introduce students to robotics, movement, and control using a two-wheel robot car powered by the Calliope mini. Learners will program the robot to move forward, turn, and respond to commands. This project helps students understand motors, direction, and problem-solving through hands-on experimentation. By connecting the robot to vehicles they see every day, students learn how machines follow instructions to move safely and efficiently. The project builds teamwork, creativity, and confidence while strengthening foundational robotics and coding skills.

IMPORATNT: This robot uses two power sources:

• 3V battery pack → powers the Calliope Mini

• 12V battery pack → powers the motors through the L298N

⚠️ The Calliope Mini is NOT powered from the motor driver.
Only signal wires go between the Calliope and the L298N.

Step 1: Power the Calliope Mini

• Connect the 3V battery pack directly to the Calliope Mini battery connector

Note: This battery powers only the Calliope Mini

• Do not connect the Calliope to the 12V battery
• Do not connect Calliope to the L298N 5V pin

Step 2: Power the L298N Motor Driver

• Connect 12V battery (+) → L298N Motor Driver +12V

• Connect 12V battery (–) → L298N Motor Driver GND

Note: The 12V battery powers only the motors

Step 3: Connect Grounds (VERY IMPORTANT)

• Connect L298N Motor Driver GND → Calliope Mini GND

Note: This creates a common ground, allowing the Calliope’s control signals to work correctly.

Step 4: Connect Motors to the L298N Moto Driver

• Motor A output → Left wheel motor

• Motor B output → Right wheel motor

Note: If the robot moves backward, swap the motor wires.

Step 5: Connect Calliope Control Pins to L298N Moto Driver

These wires carry control signals only not power

• L298N IN1 → Calliope Pin P3

• L298N IN2 → Calliope Pin P4

• L298N IN3 → Calliope Pin P5

• L298N IN4 → Calliope Pin P6

Step 6: Connect the Ultrasonic Sensor

The ultrasonic sensor is powered from the motor driver, not the Calliope:

• Ultrasonic VCC → L298N 5V

• Ultrasonic GND → L298N GND

• Ultrasonic TRIG → Calliope Pin P0

• Ultrasonic ECHO → Calliope Pin P1

How the System Works

• The ultrasonic sensor measures the distance in front of the robot
• The Calliope Mini reads the distance value
• If the distance is greater than 20 cm, the Calliope sends signals to the L298N motor driver to move forward
• If an obstacle is detected, the Calliope immediately stops the motors

Follow these steps carefully to open and explore the project in MakeCode for Calliope Mini:

• Click this link to open the project code in MakeCode

• When you open the link, you will see a few colorful blocks that makes the project.

• Next, click Edit Code tab to be directed to the MakeCode editor

Plug in your Calliope Mini to your computer using a USB cable, then follow the steps in the video to upload your code and bring your project to life!

• Robot does not move?
  Check motor wires are connected to OUT1/OUT2 and OUT3/OUT4 on L298N.
• Robot never stops?
  Ensure TRIG is on P0 and ECHO on P1.
• Distance always reads 0?
  Sensor may be blocked or wired incorrectly.
• Motors are weak or slow?
  Use fresh batteries (minimum 6V).

• How L298N motor drivers power DC motors

• How ultrasonic sensors measure distance

• How microcontrollers make decisions and control robots

• How autonomous navigation systems work in real robotics

• How to combine motors, sensors, and logic into a smart machine

• Add a servo motor to rotate the ultrasonic sensor left and right.

• Program the robot to turn left or right instead of just stopping.

• Add LEDs:

  • Green = moving

  • Red = obstacle detected

• Add a buzzer that sounds when the robot stops.

• Add a reset button to restart movement.

• Turn it into a maze-avoiding robot.

Students can use Edge Impulse (TinyML) to train a model for:

• Recognizing hand gestures to control the robot

• Predicting the best turning direction using past obstacle data

• Detecting clap sounds to stop or start the robot

This transforms the robot into an AI-powered autonomous car, just like real self-driving vehicles.