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Setup — Arduino IDE & ESP32

Do this before Week 1

Lab 1 starts with everyone wiring motors. If you arrive with a laptop that cannot talk to an ESP32, you will spend the session installing drivers instead of doing the lab — and the session is only 90 minutes.

Budget 45 minutes at home.

1. Install the Arduino IDE

Download and install from arduino.cc/en/software.

2. Add ESP32 board support

  1. Open File → Preferences.

  2. In Additional boards manager URLs, paste:

    https://espressif.github.io/arduino-esp32/package_esp32_index.json

  3. Open Tools → Board → Boards Manager, search esp32, and install esp32 by Espressif Systems.

  4. Select your board under Tools → Board → ESP32 Arduino. TODO — instructor: confirm the exact board entry for the kit (commonly ESP32 Dev Module).

3. USB driver and port

The ESP32 talks over a USB-to-serial chip. Check the small square chip next to the USB connector to know which driver you need.

Windows usually installs the driver automatically. If no port appears under Device Manager → Ports (COM & LPT):

  • Chip marked CP2102 → install the Silicon Labs CP210x VCP driver.
  • Chip marked CH340 / CH9102 → install the WCH CH34x driver.

Get drivers from the manufacturer's own site. Third-party driver sites that bundle installers are a known malware vector.

Recent macOS includes both drivers. Check the port appeared:

ls /dev/cu.*

Look for /dev/cu.usbserial-* or /dev/cu.SLAB_USBtoUART. If nothing shows up, install the CP210x or CH34x driver, then approve it in System Settings → Privacy & Security — macOS blocks new drivers silently and you have to go press the button.

The drivers are already in the kernel. The problem on Linux is permissions:

ls -l /dev/ttyUSB* /dev/ttyACM*

The port is owned by group dialout. Add yourself:

sudo usermod -aG dialout $USER

Log out and back in

Group membership is read at login. A new terminal is not enough — you must log out and in. Check with groups and look for dialout.

The single most common failure: a charge-only USB cable

Many USB cables carry power but no data. They charge a phone fine and are useless here — the board lights up and no serial port ever appears. If your board powers on but no port shows, suspect the cable before the driver.

Checkpoint — port visible

Plug in the board and confirm a port appears under Tools → Port. Note its name (COM4, /dev/ttyUSB0, /dev/cu.usbserial-0001). Everything below depends on this.

4. Upload a test sketch

File → New, paste this, and upload with the → arrow:

setup_test.ino
// TODO: confirm the onboard LED pin for the kit's board.
// GPIO 2 is correct for most ESP32 dev boards.
const int LED_PIN = 2;

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  Serial.println("ME 222 - setup OK");
}

void loop() {
  digitalWrite(LED_PIN, HIGH);
  delay(500);
  digitalWrite(LED_PIN, LOW);
  delay(500);
  Serial.printf("up %lu ms\n", millis());
}

Open Tools → Serial Monitor and set the baud rate to 115200. You should see:

ME 222 - setup OK
up 1003 ms
up 2005 ms
Upload fails — Failed to connect to ESP32: Timed out waiting for packet header

The board is not entering bootloader mode. In order of likelihood:

  1. Charge-only cable. Swap it.
  2. Hold the BOOT button. Press and hold BOOT (sometimes IO0), start the upload, release when "Connecting…" turns to dots. Many boards need this every time; it is not a fault.
  3. Serial Monitor is open. Only one program can hold the port. Close it.
  4. USB hub. Plug straight into the laptop.
Serial Monitor shows garbage characters

Baud rate mismatch. Set the dropdown to 115200 to match Serial.begin(115200).

Nothing blinks but serial works

Your board's LED is on a different pin, or it has none. Try LED_PIN = 5. If serial works, your toolchain is fine — move on.

Checkpoint — done

Blinking LED and uptime printing. That is the whole toolchain proven.

Useful snippets

Scan the I2C bus — the first thing to run whenever a sensor goes quiet in Labs 3–5:

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);   // SDA, SCL
  Serial.println("scanning...");
  for (uint8_t a = 1; a < 127; a++) {
    Wire.beginTransmission(a);
    if (Wire.endTransmission() == 0) Serial.printf("found 0x%02X\n", a);
  }
  Serial.println("done");
}

void loop() {}

Non-blocking timing — you need this from Lab 5 onward, once the car has to sense and drive at the same time. delay() stops everything:

unsigned long last = 0;
const unsigned long PERIOD = 20;   // ms

void loop() {
  unsigned long now = millis();
  if (now - last >= PERIOD) {
    last = now;
    // control loop body — runs every 20 ms
  }
}

CSV logging — use this format from Lab 5 so data pastes straight into a spreadsheet:

Serial.printf("%lu,%d,%d,%ld,%ld,%d\n", millis(), pwmL, pwmR, encL, encR, dist);