Circuits & Silicon.
C++ Firmware.
Robots in Real Space.

// Autonomous Sonar Obstacle Avoidance Rover
const int TRIG_PIN = 9;
const int ECHO_PIN = 10;
const int MOTOR_L_PWM = 5;
const int MOTOR_R_PWM = 6;

void setup() {
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);
  float distanceCM = duration * 0.034 / 2.0;

  if (distanceCM < 20.0) {
    executeAvoidance();
  } else {
    analogWrite(MOTOR_L_PWM, 180);
    analogWrite(MOTOR_R_PWM, 180);
  }
}

// Dual IR Photodiode Course Correction Loop
const int SENSOR_LEFT = A0;
const int SENSOR_RIGHT = A1;
const int THRESHOLD = 550;

void loop() {
  int valLeft = analogRead(SENSOR_LEFT);
  int valRight = analogRead(SENSOR_RIGHT);

  if (valLeft > THRESHOLD && valRight > THRESHOLD) {
    driveForward(200);
  } else if (valLeft <= THRESHOLD) {
    steerRight(160);
  } else if (valRight <= THRESHOLD) {
    steerLeft(160);
  }
}

// 4-Axis Articulated Servo Manipulator
#include <Servo.h>

Servo baseServo;
Servo elbowServo;
Servo wristServo;
Servo clawServo;

void pickupSequence() {
  baseServo.write(90);   // Center azimuth
  elbowServo.write(45);  // Lower arm
  clawServo.write(120);  // Clamp payload
  delay(300);
  elbowServo.write(110); // Lift arm
}