esp8266-OLED, esp8266-Arduino library for I2C-OLED displays

esp8266-OLED is an esp8266-Arduino library for I2C-OLED displays. This post show how to download and install to Arduino IDE, and test with example.

- It's assumed you are programming NodeMCU on Arduino Software, with ESP8266 core for Arduino installed.

- Connect I2C OLED to NodeMCU.

OLED VCC - NodeMCU 3v3
OLED GND - NodeMCU GND
OLED SCL - NodeMCU D1
OLED SDA - NodeMCU D2

(reamrk: the Fritzing parts of can OLED_SSD1306_I2C_128x64 can be download HERE)


- Add esp8266-OLED library to Arduino Software:
visit https://github.com/klarsys/esp8266-OLED, follow the steps to install the library:

• Click on the Download ZIP button in the top right corner.
• Uncompress it.
• Rename the uncompressed folder to OLED.
• Check that the OLED folder contains OLED.cpp and OLED.h files.
• Place the OLED folder in your <arduinosketchfolder>/libraries/ folder - you may need to create the libraries subfolder if it is your first library.
• Restart the IDE.

Open the example,
File > Examples > ESP8266-OLED Display Library > example

In order to match with our connection, we have to modify it to correct SDA and SCL pins:
change the code:
OLED display(2, 14);

to
OLED display(4, 5);

where 4, 5 correspond to NodeMCU D2 and D1. Refer to the "The pin definition" in NodeMCU - ESP8266/CP2102.

// Example sketch for testing OLED display

// We need to include Wire.h for I2C communication
#include <Wire.h>
#include "OLED.h"

// Declare OLED display
// display(SDA, SCL);
// SDA and SCL are the GPIO pins of ESP8266 that are connected to respective pins of display.
OLED display(4, 5);

void setup() {
  Serial.begin(9600);
  Serial.println("OLED test!");

  // Initialize display
  display.begin();

  // Test message
  display.print("Hello World");
  delay(3*1000);

  // Test long message
  display.print("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.");
  delay(3*1000);

  // Test display clear
  display.clear();
  delay(3*1000);

  // Test message postioning
  display.print("TOP-LEFT");
  display.print("4th row", 4);
  display.print("RIGHT-BOTTOM", 7, 4);
  delay(3*1000);

  // Test display OFF
  display.off();
  display.print("3rd row", 3, 8);
  delay(3*1000);

  // Test display ON
  display.on();
  delay(3*1000);
}

int r = 0, c = 0;

void loop() {
  r = r % 8;
  c = micros() % 6;

  if (r == 0)
    display.clear();

  display.print("Hello World", r++, c++);

  delay(500);
}

Result:

---

Related:
- Another library of I2C OLED for ESP8266 core for Arduino - Adafruit SSD1306 library
- esp8266-oled-ssd1306 library