ABOUT THIS PROJECT

We name it RobotO. This is the version 3 so it is RobotO.3. Let's introduce, RobotO.3 is an Arduino UNO based object avoidance and Table edge detection or fall prevention robot which uses HC-SR04 ultrasonic sensors in order to detect obstacle and IR Sensor Module in order to detect edge to prevent fall from the table.

RobotoO.3is the third iteration of RobotO series so it has many features. So basically it can run in two mode. One is automatic mode and second one is manual mode controlled by Android mobile via Bluetooth. It uses HC-05 Bluetooth module for communication.

Manual Mode:

By default is a manual mode or we can send the command mo:0 via mobile through the RobotO App or any Arduino controller app to put it into manual mode. In this mode, It can be controlled via RobotO App like in forward, left, right and reverse direction. We can control speed, direction and also play melody/ horn.

Automatic Mode:

By sending mo:1 command we can put it into automatic mode. In this mode, It takes automatic decision based on sensors data. If obstacle detected in his path it gives horn if obstacle removed, It continue moving in same direction if not it turn left or right by checking left and right way using servo 9g motor and ultrasonic. If all the direction get blocked by obstacle then it stops and play melody!

Main Features:

Mode: Automatic and Remote control

Obstacle detection capabilities

Fall prevention or Table edge detection

Plays horn and melody.

Speed control

Command List:

Mode Automatic: mo:1

Mode Manual: mo:0

Melody: ml

Speed: sp:255 (0-255)

Servo: sr:180 (0-180)

Horn: tn:500 (time millis)

Kinematic Survival: The Edge-Detecting Rover Architecture

An obstacle-avoidance robot using purely an ultrasonic sensor is functionally blind! It works flawlessly preventing massive wall collisions, but if placed on a table, the ultrasonic sensor fires into the empty room, returning "SAFE", immediately causing the robot to drive violently off the absolute cliff and shatter its motors onto the concrete floor! The Table Edge Detection Robot completely remedies this geometrical nightmare! By mounting hyper-sensitive Infrared (IR) Proximity Sensors directly underneath the front chassis, pointing aggressively towards the floor, the Arduino continuously checks for "Ground." The instant the IR beam fails to bounce back natively, it calculates a massive cliff anomaly and violently triggers an emergency kinematic REVERSE protocol immediately!

The Deep IR "Cliff Sensor" Hardware Matrix

An IR Obstacle sensor (TCRT5000 or IR Proximity Module) blasts invisible infrared photons completely downwards.

1. If the table is immediately below (e.g., < 2 inches), the photons reflect violently back onto the Photodiode. The sensor's Digital Pin outputs LOW (0V) indicating "Ground Secure!"
2. The instant the rover's wheels dangle over the edge, the photons completely escape into the empty air of the room! The sensor output violently clicks HIGH (5V) signaling a horrifying "CLIFF DETECTED!" anomaly!

int cliffSensorLeft = 4;
int cliffSensorRight = 5;

void loop() {
  int groundStatusLeft = digitalRead(cliffSensorLeft);
  int groundStatusRight = digitalRead(cliffSensorRight);

  // If ANY sensor loses the ground reflection completely!
  if (groundStatusLeft == HIGH || groundStatusRight == HIGH) {
    // ABORT FORWARD VELOCITY IMMEDIATELY!
    ReverseMotorsViolently();
    delay(500); // 500ms of aggressive reverse thrust to save the chassis!
    
    SpinRight180Degrees(); // Pivot radically away from the abyss!
    delay(400); 
  } else {
    // Main HC-SR04 Wall Obstacle Avoidance Array executes normally
    executeStandardUltrasonicAlgorithm(); 
  }
}

The L298N Power Isolation Priority!

Running violent ReverseMotorsViolently() commands requires the heavy L298N H-Bridge Motor Driver to completely invert polarity across the TT Gear Motors instantly!

• This causes severe terrifying "Back EMF" voltage spikes to ripple backwards completely through the 5V power supply!
• If the Arduino and the L298N share the absolute exact same fragile battery matrix, the processor will frequently reset entirely the exact second you hit a table edge, causing the robot to plunge to its doom anyway!
• You MUST utilize entirely separated Power Sources or ensure the L298N has massive 7.4V/12V packs heavily decoupled logically from the Arduino's specific 5V Logic input!

Advanced Rover Survival Components

• Arduino Uno Rev3 (Primary Kinematic decision engine).
• L298N Dual Motor Driver Module (Explicitly required to route massive PWM thrust currents into the DC wheels).
• HC-SR04 Forward Ultrasonic Sensor mounted on an SG90 Servo Turret (To continuously scan the absolute immediate XYZ physical room coordinates).
• Two Downward-Facing Optical IR Proximity Sensors (The absolute life-saving "Cliff Sensor" matrix, rigidly tuned utilizing their onboard potentiometers to aggressively detect < 5cm table distances exactly!).