Documentation

Arduino IDE setup for the ESP32-CAM:
1. File > Preferences > Additional Boards Manager URLs:
   https://espressif.github.io/arduino-esp32/package_esp32_index.json
2. Tools > Board > Boards Manager > install "esp32"
3. Tools > Board > "AI Thinker ESP32-CAM"
4. File > Examples > ESP32 > Camera > CameraWebServer
   - select CAMERA_MODEL_AI_THINKER in the sketch
   - enter your Wi-Fi SSID and password
5. GPIO 0 jumper ON, reset, Upload; jumper OFF, reset
6. Open Serial Monitor (115200) - it prints the stream URL
7. Visit that URL in a browser: live video confirms the
   board, camera, and Wi-Fi all work before the car does

// Bench test with the car's wheels OFF the ground.
// Match these pins to your driver wiring (Motor Wiring tab).
const int L_FWD = 12, L_REV = 13;   // left pair
const int R_FWD = 14, R_REV = 15;   // right pair

void setup() {
  pinMode(L_FWD, OUTPUT); pinMode(L_REV, OUTPUT);
  pinMode(R_FWD, OUTPUT); pinMode(R_REV, OUTPUT);
}

void allStop() {
  digitalWrite(L_FWD, LOW); digitalWrite(L_REV, LOW);
  digitalWrite(R_FWD, LOW); digitalWrite(R_REV, LOW);
}

void loop() {
  // forward - all four wheels should spin the same way
  digitalWrite(L_FWD, HIGH); digitalWrite(R_FWD, HIGH);
  delay(1500);
  allStop(); delay(500);

  // spin in place - left pair back, right pair forward
  digitalWrite(L_REV, HIGH); digitalWrite(R_FWD, HIGH);
  delay(1500);
  allStop(); delay(1500);
  // Any wheel turning the wrong way: swap that motor's two leads.
}

// Bare-bones browser control: the car hosts its own Wi-Fi AP.
// Connect to "ESP32-CAR" and visit http://192.168.4.1/forward etc.
#include <WiFi.h>
#include <WebServer.h>

const int L_FWD = 12, L_REV = 13, R_FWD = 14, R_REV = 15;
WebServer server(80);

void drive(bool lf, bool lr, bool rf, bool rr) {
  digitalWrite(L_FWD, lf); digitalWrite(L_REV, lr);
  digitalWrite(R_FWD, rf); digitalWrite(R_REV, rr);
  server.send(200, "text/plain", "ok");
}

void setup() {
  for (int p : {L_FWD, L_REV, R_FWD, R_REV}) pinMode(p, OUTPUT);
  WiFi.softAP("ESP32-CAR", "drive1234");
  server.on("/forward", []() { drive(1, 0, 1, 0); });
  server.on("/back",    []() { drive(0, 1, 0, 1); });
  server.on("/left",    []() { drive(0, 1, 1, 0); });
  server.on("/right",   []() { drive(1, 0, 0, 1); });
  server.on("/stop",    []() { drive(0, 0, 0, 0); });
  server.begin();
}

void loop() {
  server.handleClient();
}

"Brownout detector was triggered" in the Serial Monitor means
the 5V rail sagged. Work down this list:

1. Fresh / charged 18650 cells (tired cells sag under motor load)
2. Motors on battery power, never on the USB-serial adapter
3. Thick, short power leads to the ESP32-CAM; add a 470-1000 uF
   capacitor across its 5V/GND if resets happen when motors start
4. Camera + Wi-Fi alone can draw ~300 mA peaks - budget for it
5. Antenna near battery leads or metal deck = weak Wi-Fi;
   reposition the board so the antenna area hangs clear