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Arduino Setup

Install the toolchain you'll use for every workshop in this section, then upload two starter sketches: a blink and a WiFi connect.

Install Arduino IDE​

We use the Arduino IDE as the development environment for every workshop. It's free, easy to install, and gets you up and running fast. Pick your operating system and follow the installer.

Pro tip

If you're an experienced developer and want a more advanced editor, look at PlatformIO for VS Code, or the Espressif Arduino SDK. For beginners, stick with the Arduino IDE.

Set up your microcontroller​

Once the IDE is installed, add support for ESP32 boards.

Step 1: Install ESP32 board support​

The ESP32 package is available directly in the Arduino IDE Boards Manager.

  1. Open Arduino IDE.
  2. Go to Tools → Board → Boards Manager.
  3. Search for esp32.
  4. Find "esp32 by Espressif Systems" in the list.
  5. Click Install (this may take a few minutes).
  6. Wait for the installation to finish.

Install CH340 driver (CYD users)​

If you're using a Cheap Yellow Display, you'll need the CH340 driver:

  1. Download from the SparkFun CH340 driver guide.
  2. Install it following the instructions for your OS.

Step 2: Select your board​

After installation, select the board:

USB cable matters

Use a USB cable that supports data transfer, not just charging. Many cheap USB cables and the cables that ship with power banks are charging-only - the data lines aren't connected. If your computer doesn't recognise your ESP32, swap cables.

  1. Connect your ESP32 to your computer via USB.
  2. Go to Tools → Board → esp32.
  3. Select ESP32C3 Dev Module (or the variant that matches your board).
  4. Go to Tools → Port and pick the port your ESP32 is on:
    • Windows: usually COM3, COM4, etc.
    • macOS: usually /dev/cu.usbserial-* or /dev/cu.SLAB_USBtoUART.
    • Linux: usually /dev/ttyUSB0 or /dev/ttyACM0.

Your first sketch​

Upload a blink sketch to confirm the toolchain works.

LED pin

This sketch uses pin 8 on the ESP32-C3. On the Cheap Yellow Display (CYD), the LED is on pin 4.

// Define the pin number for the LED
#define LED_PIN 8

// Setup function is called once when the microcontroller starts up.
void setup() {
    pinMode(LED_PIN, OUTPUT); // Set the LED pin as an output.
}

// Loop function is called repeatedly.
void loop() {
    digitalWrite(LED_PIN, HIGH); // Turn the LED on (HIGH is the voltage level).
    delay(1000); // Wait for 1 second.
    digitalWrite(LED_PIN, LOW); // Turn the LED off by making the voltage LOW.
    delay(1000); // Wait for 1 second.
}

Copy the code into the Arduino IDE and upload it. The on-board LED should blink.

Source: Workshop-01/examples/blink/blink.ino

Connect to WiFi​

Now connect your microcontroller to WiFi.

#include <WiFi.h> // Include the WiFi library for ESP32
const char* ssid = "Your SSID"; // Your WiFi SSID
const char* password = "Your Password"; // Your WiFi Password

// Setup function is called once when the microcontroller starts up.
void setup() {
    Serial.begin(115200); // Initialize the serial communication at 115200 baud rate
    WiFi.mode(WIFI_STA); // Set WiFi mode to Station (client mode)
    WiFi.setTxPower(WIFI_POWER_8_5dBm); // Workaround for ESP32-C3 Super Mini
    WiFi.begin(ssid, password); // Connect to WiFi using the SSID and Password
    // Wait for the connection to be established
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000); // Wait for 1 second
        Serial.println("Connecting to WiFi..."); // Print "Connecting to WiFi..." to the serial monitor
    }
    Serial.println("Connected to WiFi"); // Print "Connected to WiFi" to the serial monitor
    Serial.println("IP address: "); // Print "IP address: " to the serial monitor
    Serial.println(WiFi.localIP()); // Print the IP address to the serial monitor
}

// Loop function is called repeatedly.
void loop() {
    // Check if the WiFi connection is lost
    if (WiFi.status() != WL_CONNECTED) {
        // Print "WiFi connection lost. Reconnecting..." to the serial monitor
        Serial.println("WiFi connection lost. Reconnecting...");
        WiFi.reconnect(); // Reconnect to WiFi
        // Wait for the connection to be established
        while (WiFi.status() != WL_CONNECTED) {
            delay(1000); // Wait for 1 second
            Serial.print("."); // Print "." to the serial monitor
            Serial.print(".");
        }
        Serial.println("Reconnected!"); // Print "Reconnected!" to the serial monitor
    }
}

Update SSID/password, upload, and watch the serial monitor - you should see the IP address printed.

Source: Workshop-01/examples/wifi/wifi.ino

ESP32-C3 Super Mini WiFi workaround

If you're using an ESP32-C3 Super Mini and hit WiFi connection issues, the sketch includes WiFi.setTxPower(WIFI_POWER_8_5dBm); as a workaround. This sets the transmit power to 8.5 dBm and resolves connectivity problems specific to that board variant.

Serial Monitor

Open it via Tools → Serial Monitor or Ctrl+Shift+M (Cmd+Shift+M on Mac). Set the baud rate to 115200 to match the sketch.

Further Resources​

Adapted from the CardanoThings workshop series, originally produced under Project Catalyst Fund 11. Source code: github.com/CardanoThings/Workshops/Workshop-01.