How to Use ESP32-C3-0.42 OLED: Examples, Pinouts, and Specs

The ESP32-C3-0.42 OLED is a versatile development board designed by 01Space that combines the powerful ESP32-C3 microcontroller with a compact 0.42-inch OLED display. This board is ideal for IoT projects, wearable devices, and smart home applications where visual feedback is necessary. The integrated WiFi and Bluetooth capabilities of the ESP32-C3 allow for easy connectivity and remote data exchange.

• Microcontroller: ESP32-C3
• Display: 0.42-inch OLED
• Connectivity: WiFi 802.11 b/g/n, Bluetooth 4.2/5.0 LE
• Flash Memory: 4MB
• SRAM: 400 KB
• GPIO Pins: 22
• ADC Channels: 6
• Operating Voltage: 3.3V
• Operating Temperature: -40°C to +85°C

Note: The full pinout will be provided by the manufacturer or can be found in the detailed datasheet.

To use the 0.42-inch OLED display, you'll need to connect it to the ESP32-C3's I2C pins. Here's a simple example of how to wire the display to the ESP32-C3:

• OLED SDA (Serial Data) -> ESP32-C3 IOx (configured as I2C SDA)
• OLED SCL (Serial Clock) -> ESP32-C3 IOy (configured as I2C SCL)
• OLED VCC -> 3V3
• OLED GND -> GND

1. Install the required drivers for the USB-to-UART bridge chip used on the board.
2. Use the Arduino IDE or ESP-IDF to write and upload your code to the ESP32-C3.
3. Ensure the board is in bootloading mode if necessary (usually by holding the BOOT button while resetting the board).

• Always disconnect the board from power before making or altering connections.
• Use a logic level converter if interfacing with components that operate at different voltage levels.
• Avoid drawing too much current from the GPIO pins to prevent damage to the board.

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 32 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  // Initialize OLED display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000); // Pause for 2 seconds

  // Clear the buffer
  display.clearDisplay();

  // Draw a single pixel in white
  display.drawPixel(10, 10, SSD1306_WHITE);

  // Display the drawing
  display.display();
}

void loop() {
  // Code to update the display continuously
}

Note: The above code is for interfacing with a generic SSD1306 OLED display using the Adafruit SSD1306 library. Adjust the I2C address (0x3C) and screen dimensions if necessary for the specific OLED model on the ESP32-C3-0.42 OLED board.

• Display not lighting up: Ensure that the OLED is correctly wired to the ESP32-C3 and that the I2C address matches the one in your code.
• WiFi/Bluetooth not functioning: Check that the antenna is properly connected and that your code correctly initializes the WiFi/Bluetooth module.
• Board not recognized by computer: Verify that the correct drivers are installed and that the USB cable is functioning.

Q: Can I power the ESP32-C3-0.42 OLED with a battery? A: Yes, you can power it with a battery, but ensure that the voltage is regulated to 3.3V.

Q: What is the maximum current draw from a GPIO pin? A: The maximum current per I/O pin should not exceed 12 mA.

Q: How do I update the firmware on the ESP32-C3? A: Firmware updates can be done through the UART interface using the bootloader mode or over-the-air (OTA) if your code supports it.

For further assistance, consult the manufacturer's documentation or contact 01Space support.