Desktop Rover Accessories: Upgrades, Sensors, and Custom Skins

• Setup: define pins, initialize serial, set pin modes.
• Loop: read sensor(s), check remote commands (if any), decide motor outputs, write PWM values.

Example Arduino code (drive forward, stop on obstacle):

// Example for Arduino with L298N and HC-SR04 const int trigPin = 9; const int echoPin = 10; const int enA = 5; // PWM left const int in1 = 2; const int in2 = 3; const int enB = 6; // PWM right const int in3 = 4; const int in4 = 7; long readDistanceCM() {   digitalWrite(trigPin, LOW);   delayMicroseconds(2);   digitalWrite(trigPin, HIGH);   delayMicroseconds(10);   digitalWrite(trigPin, LOW);   long duration = pulseIn(echoPin, HIGH, 30000);   long distance = duration * 0.034 / 2;   return distance; } void setup() {   pinMode(trigPin, OUTPUT);   pinMode(echoPin, INPUT);   pinMode(enA, OUTPUT);   pinMode(enB, OUTPUT);   pinMode(in1, OUTPUT);   pinMode(in2, OUTPUT);   pinMode(in3, OUTPUT);   pinMode(in4, OUTPUT);   Serial.begin(9600); } void forward(int speed) {   digitalWrite(in1, HIGH);   digitalWrite(in2, LOW);   analogWrite(enA, speed);   digitalWrite(in3, HIGH);   digitalWrite(in4, LOW);   analogWrite(enB, speed); } void stopMotors() {   analogWrite(enA, 0);   analogWrite(enB, 0); } void loop() {   long dist = readDistanceCM();   Serial.println(dist);   if (dist > 20 || dist == 0) { // 0 if no echo     forward(180);   } else {     stopMotors();     delay(500);     // simple avoidance: turn right briefly     digitalWrite(in1, LOW);     digitalWrite(in2, HIGH);     digitalWrite(in3, HIGH);     digitalWrite(in4, LOW);     analogWrite(enA, 180);     analogWrite(enB, 180);     delay(400);   }   delay(100); } 

Step 5 — Testing, calibration, and troubleshooting

Testing checklist:

• Motors respond to simple on/off commands.
• Rover drives straight when both motors are given equal PWM—trim motor speed in code if needed.
• Sensor readings are stable (filter noisy values with averaging).
• Battery provides sufficient voltage under load; check voltage drop when motors start.

Common fixes:

• Rover veers: adjust wheel alignment, add code-based PWM offsets.
• Motors not spinning: check motor driver enable pins and power supply.
• Ultrasonic false reads: ensure sensor mounted horizontally and away from reflective edges.

Optional upgrades and expansions

• Wireless control: Bluetooth module (HC-05/06) or Wi‑Fi (ESP8266/ESP32) for smartphone/PC control.
• Camera: Pi Camera on Raspberry Pi Zero or USB camera for video streaming and vision.
• Autonomous behaviors: line following (IR sensors), SLAM basics with lidar (higher cost), obstacle mapping.
• Better power: switch to rechargeable LiPo with proper regulator and a battery protection circuit.
• Aesthetics: 3D‑printed shells, LED lights, paint.

Project timeline and difficulty

• Estimated time: 4–12 hours for a basic rover (parts dependent).
• Difficulty: beginner-friendly; prior soldering or Arduino experience helpful but not required.
• Cost estimate: \(30–\)120 depending on parts (cheap clone motor drivers and ultrasonic sensors are inexpensive; cameras and advanced sensors raise cost).

Final tips

• Start simple: get motors and basic drive working before adding sensors or remote control.
• Keep wiring clean and modular—use connectors so you can swap parts without re-soldering.
• Document pinouts and code versions; small notes save time during debugging.
• Use community resources: Arduino forums, Instructables, and YouTube for visuals when stuck.

Building a desktop rover is a compact way to learn robotics fundamentals and create a platform you can expand for many projects. Enjoy the process and iterate—each upgrade teaches a new skill.