How to Use I2C IIC Serial OLED LCD Screen: Examples, Pinouts, and Specs

The I2C IIC Serial OLED LCD Screen is a compact display module designed for use in embedded systems. Manufactured in China, this module leverages OLED (Organic Light Emitting Diode) technology to deliver high contrast, low power consumption, and excellent visibility. It communicates via the I2C (Inter-Integrated Circuit) protocol, making it easy to interface with microcontrollers such as Arduino, Raspberry Pi, and other development boards.

• Displaying text, graphics, or sensor data in embedded systems
• Creating user interfaces for IoT devices
• Monitoring system status in industrial applications
• Prototyping and educational projects

Below are the key technical details of the I2C IIC Serial OLED LCD Screen:

The module typically has a 4-pin interface for I2C communication. The pinout is as follows:

1. Connect the Pins:

   • Connect the GND pin to the ground of your microcontroller.
   • Connect the VCC pin to the 3.3V or 5V power supply of your microcontroller.
   • Connect the SCL pin to the I2C clock line (SCL) of your microcontroller.
   • Connect the SDA pin to the I2C data line (SDA) of your microcontroller.

2. Install Required Libraries:

   • For Arduino, install the Adafruit_GFX and Adafruit_SSD1306 libraries from the Arduino Library Manager.

3. Write and Upload Code:

   • Use the example code below to display text or graphics on the screen.

#include <Wire.h>                  // Include the Wire library for I2C
#include <Adafruit_GFX.h>          // Include the Adafruit GFX library
#include <Adafruit_SSD1306.h>      // Include the Adafruit SSD1306 library

#define SCREEN_WIDTH 128           // OLED display width, in pixels
#define SCREEN_HEIGHT 64           // OLED display height, in pixels

// Declaration for SSD1306 display connected using I2C
#define OLED_RESET -1              // Reset pin (not used with I2C)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  // Initialize the display
  if (!display.begin(SSD1306_I2C_ADDRESS, 0x3C)) { 
    // Address 0x3C is the default for most SSD1306 modules
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);                     // Don't proceed, loop forever
  }

  display.clearDisplay();         // Clear the buffer
  display.setTextSize(1);         // Set text size to 1 (smallest)
  display.setTextColor(SSD1306_WHITE); // Set text color to white
  display.setCursor(0, 0);        // Set cursor to top-left corner
  display.println(F("Hello, OLED!")); // Print text to the display
  display.display();              // Display the text
}

void loop() {
  // Nothing to do here
}

• Ensure the I2C address of the OLED module matches the address in your code. The default is usually 0x3C but may vary depending on the module.
• Use pull-up resistors (typically 4.7kΩ) on the SCL and SDA lines if your microcontroller does not have internal pull-ups.
• Avoid exceeding the operating voltage range (3.3V - 5V) to prevent damage to the module.
• Handle the module carefully to avoid damaging the OLED screen.

1. The screen does not turn on:

   • Verify the power connections (GND and VCC) and ensure the correct voltage is supplied.
   • Check the I2C address in your code. Use an I2C scanner sketch to detect the module's address.

2. The display shows garbled or no text:

   • Ensure the Adafruit_GFX and Adafruit_SSD1306 libraries are correctly installed.
   • Verify the SCL and SDA connections. Ensure they are connected to the correct pins on your microcontroller.

3. The screen flickers or behaves erratically:

   • Add pull-up resistors to the SCL and SDA lines if not already present.
   • Check for loose or poor connections in the circuit.

Q: Can I use this module with a 3.3V microcontroller?
A: Yes, the module supports both 3.3V and 5V logic levels.

Q: What is the maximum cable length for I2C communication?
A: The maximum length depends on the pull-up resistor values and the I2C clock speed. For standard setups, keep the cable length under 1 meter.

Q: Can I display images on this screen?
A: Yes, you can display monochrome bitmaps using the Adafruit_SSD1306 library.

Q: How do I change the I2C address of the module?
A: Some modules allow changing the address by soldering jumpers on the back. Refer to the module's datasheet for details.

By following this documentation, you can effectively integrate the I2C IIC Serial OLED LCD Screen into your projects and troubleshoot common issues.