Using LCD

Small OLED I2C display allows display many information with just 2 (Analog) control lines. See name of controller to select library. I had SSD1306.

There are mey libraries which allow using this display.

Wiring

My display used 3.3V, so be careful!

I2C protocol states how should wiring be done (according to Wire library):

If your board is not listed (for example my Arduino Pro Mini), see their personal pages with specifications (for Pro Mini - it says I2C is same as for Uno).

Adafruit SSD1306

This one is claimed to be most popular. I’ve installed it, and even managed to compile example. As a result - almost all of my memory was spent on this library, and I could not end up with any visible result.

U8glib

Also available in Arduino libraries collection. Easy to use. Long to compile, but resulting binary is surprizingly (compared to adafruit) small.

#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0);  // I2C / TWI

void setup() {
  // put your setup code here, to run once:
  u8g.setFont(u8g_font_unifont);
  u8g.drawStr( 0, 22, "Hello World!");

  // assign default color value
  if ( u8g.getMode() == U8G_MODE_R3G3B2 ) {
    u8g.setColorIndex(255);     // white
  } else if ( u8g.getMode() == U8G_MODE_GRAY2BIT ) {
    u8g.setColorIndex(3);       // max intensity
  } else if ( u8g.getMode() == U8G_MODE_BW ) {
    u8g.setColorIndex(1);       // pixel on
  } else if ( u8g.getMode() == U8G_MODE_HICOLOR ) {
    u8g.setHiColorByRGB(255,255,255);
  }
}

void loop() {
  u8g.firstPage();
  do {
    u8g.setFont(u8g_font_unifont);
    u8g.drawStr( 0, 18, "hello,");
    u8g.drawStr( 0, 36, "how are you?");
  } while( u8g.nextPage() );

  delay(1000);
}

U8glib Github project. See for details.

Projects

See Humidity on LCD. Reads air humidity and air quality, then displays it on LCD screen.