Beginner Project: Build Otto DIY+ Bluetooth Robot with Arduino

#include <Servo.h>                           // Library for controlling servos
#include <SoftwareSerial.h>                 // Library for Bluetooth communication

// Bluetooth module on pins D11 (RX) and D12 (TX)
SoftwareSerial BT(11, 12);

// Define servo motors
Servo leftLeg, rightLeg, leftFoot, rightFoot;

void setup() {
// Start Bluetooth and Serial monitor
BT.begin(9600);
Serial.begin(9600);

// Attach servos to corresponding pins
leftLeg.attach(2);
rightLeg.attach(3);
leftFoot.attach(4);
rightFoot.attach(5);

// Set all servos to center position
centerPosition();
}

void loop() {
// Check if Bluetooth command is received
if (BT.available()) {
char cmd = BT.read();
Serial.println(cmd);             // Print received command to Serial Monitor

// Execute command
switch (cmd) {
case ‘F‘: walkForward(); break;           // Forward
case ‘B‘: walkBackward(); break;         // Backward
case ‘L‘: turnLeft(); break;            // Turn Left
case ‘R‘: turnRight(); break;          // Turn Right
case ‘D‘: dance(); break;             // Dance
case ‘S‘: centerPosition(); break;   // Stop / Reset
case ‘H‘: helloMove(); break;       // Wave Hello
}
}
}

// ———- Servo Movement Functions ———-

// Center all servos
void centerPosition() {
leftLeg.write(90);
rightLeg.write(90);
leftFoot.write(90);
rightFoot.write(90);
}

// Walk Forward
void walkForward() {
leftLeg.write(120);
rightLeg.write(60);
delay(300);
centerPosition();
delay(300);
}

// Walk Backward
void walkBackward() {
leftLeg.write(60);
rightLeg.write(120);
delay(300);
centerPosition();
delay(300);
}

// Turn Left
void turnLeft() {
leftFoot.write(60);
rightFoot.write(120);
delay(500);
centerPosition();
}

// Turn Right
void turnRight() {
leftFoot.write(120);
rightFoot.write(60);
delay(500);
centerPosition();
}

// Dance Movement
void dance() {
for (int i = 0; i < 3; i++) {
leftLeg.write(60);
rightLeg.write(120);
delay(300);
leftLeg.write(120);
rightLeg.write(60);
delay(300);
}
centerPosition();
}

// Wave Hello
void helloMove() {
for (int i = 0; i < 3; i++) {
leftFoot.write(120);
delay(300);
leftFoot.write(60);
delay(300);
}
centerPosition();
}