Obstacle-Avoiding Robot

This is a framework for a hands-on physical computing workshop. Structuring this around project-based learning ensures that every new line of code or wired component immediately serves the larger goal of building a functional, autonomous robot.

Using the Arduino Nano alongside the DRV8833 is an excellent hardware choice for beginners—it keeps the chassis compact and operates much more efficiently at lower voltages compared to older drivers like the L298N.

Here is a comprehensive 5-session workshop outline (15 hours total) designed to steadily build complexity while preventing cognitive overload.

Session 1: The Foundation – Microcontrollers, I/O, and Breadboarding

Goal: Demystify the hardware, introduce the Arduino IDE, and establish foundational programming concepts (setup, loop, variables, and basic I/O).

• Hour 1: Ecosystem & First Upload

  • Introduction to the Arduino Nano: What is a microcontroller vs. a computer?

  • Navigating the Arduino IDE: Selecting the board, COM ports, and the structure of a sketch (setup() vs loop()).

  • Activity: The "Blink" sketch. Modifying delay times to create heartbeat patterns.

• Hour 2: Breadboarding & Digital Outputs

  • How breadboards work (rails vs. rows).

  • Basic electronics safety: Why we need current-limiting resistors for LEDs.

  • Activity: Wiring an external LED. Writing code to blink the external LED.

  • Activity: Practice in cutting, stripping, and soldering wires.

• Hour 3: Serial Communication & Digital Inputs

  • Wiring a tactile button (pull-up/pull-down resistor concepts, or using INPUT_PULLUP).

  • Introduction to the Serial Monitor for debugging.

  • Activity: Pressing a button to turn on an LED, and printing the button state to the Serial Monitor.

  • Pro-Tip for Instructors: Teach students early to format their Serial output cleanly (e.g., Serial.println(sensorValue); rather than wrapping outputs in unnecessary quotation marks) to make reading rapid data streams easier.

Session 4: System Integration – Bringing the Robot to Life

Goal: Merge the motion code with the sensor code to create basic autonomous obstacle avoidance.

• Hour 1: Code Merging & State Machines

  • Strategies for combining complex sketches. Moving from linear delays to basic state logic (e.g., "If path is clear, drive forward. Else, stop and check surroundings").

  • Activity: Merging the DRV8833 motor functions with the HC-SR04 reading functions.

• Hour 2: Basic Obstacle Avoidance

  • Writing the primary logic loop.

  • Activity: Programming the robot to drive forward indefinitely until an object is detected within 15cm, at which point it calls the stopMotors() function.

• Hour 3: The "Look and Decide" Algorithm

  • Implementing decision-making logic using if/else statements.

  • Activity: When an obstacle is detected, the robot stops. The servo looks left, then right. The Arduino compares the two distance variables, determines which side has more open space, turns the chassis in that direction, and resumes driving.

Session 5: Advanced Tuning, Edge Cases, and Showcase

Goal: Refine the autonomous behavior, troubleshoot real-world physics issues, and celebrate the completed projects.

• Hour 1: Tackling Real-World Physics & Edge Cases

  • Addressing the limitations of ultrasonic sensors (e.g., angled walls deflecting sound waves, soft materials absorbing sound).

  • Replacing blocking code (delay()) with non-blocking timers (millis()) if students are ready for the challenge, allowing the robot to read sensors while driving rather than stopping to look.
    
    

• Hour 2: Track Testing & Iteration

  • Setting up an arena or obstacle course.

  • Activity: Iterative testing. Students observe their robots in the arena, identify failure points (e.g., turning too far, ignoring narrow table legs), and refine their speed variables and trigger distances.
    
    

• Hour 3: Workshop Showcase & Next Steps

  • Students demonstrate their robots navigating the course.

  • Code walkthroughs: Have students explain one custom function they are proud of.

  • Wrap-up: Discussing what sensors could be added next (line-tracking IR sensors, Bluetooth modules for remote control).