Source: https://mokxi.com/libraries/u8g2 Updated: 2026-11-02 Libraries / Displays Arduino library · Displays # U8g2: one library for almost every monochrome display U8g2, by olikraus, supports hundreds of monochrome displays: SSD1306 and SH1106 OLEDs, the SSD1309, the 128x128 SH1107, the Nokia 5110 and many LCD controllers. Its strengths are a huge font collection and memory modes that let even an Uno drive a display it could not otherwise buffer. Open the example in the editor See the calls Built in on Mokxi: #include and it builds, with nothing to install. Free, and no account needed. ## What U8g2 does The display is chosen by the constructor’s long name, and every part of it means something. U8G2_SSD1306_128X64_NONAME_F_HW_I2C is the SSD1306 controller, 128 by 64 pixels, the generic module, a full frame buffer (F) and hardware I2C. Swap F for 1 or 2 and you get a page buffer of 128 or 256 bytes; swap HW_I2C for SW_I2C and you choose the pins yourself. In full buffer mode you clear the buffer, draw and call sendBuffer(). In page mode the drawing code runs once for every strip of the screen inside a firstPage() and nextPage() loop. U8g2 also includes U8x8, a text-only interface that needs no buffer at all. Library Manager name | U8g2 Author | olikraus Include | #include #include Boards | every board Mokxi compiles for but ATtiny85 In the simulator | Runs, with a gap the note below names. Parts it drives | OLED display, 128x64, OLED display, 128x32, OLED display, 1.3 inch SH1106, OLED display, 1.12 inch SH1107, Nokia 5110 display, PCD8544 ## Install it It builds on every board Mokxi compiles for but ATtiny85. In Mokxi it is built in: #include and the sketch compiles, with no download, no zip and no Library Manager. On a real board, install "U8g2" by olikraus from the Arduino IDE’s Library Manager (Sketch, Include Library, Manage Libraries), or add U8g2 to lib_deps in PlatformIO. Mokxi follows the calls of release 2.35.30, so a sketch written here builds there too. What to know in the simulator: Every u8g2_font_* and u8x8_font_* name builds, but draws Mokxi’s 5x8 characters at the nearest whole size, so icon and non-Latin glyphs are '?'. The OLED SPI constructors and controllers with no Mokxi part (ST7920 and the rest) build and say so at begin(). MUIU8g2.h and U8g2's C API are not here. ESP32-C3 · Arduino Uno · Arduino Nano · Arduino Mega 2560 · Arduino Leonardo · SparkFun Pro Micro · Arduino Micro · ESP32-C6 · Raspberry Pi Pico · Raspberry Pi Pico W · Seeed XIAO SAMD21 · STM32 · STM32 Nucleo-F411RE · STM32 Blue Pill · micro:bit V2 · Arduino Uno R4 · ESP32 DevKit · ESP32-S3-DevKitC-1 · ESP8266 NodeMCU · Arduino Pro Mini 3.3 V · Seeed XIAO ESP32-C3 · ESP32-C3 SuperMini · Seeed XIAO ESP32-C6 · ESP32-DevKitC V4 · LOLIN32 Lite · Wemos D1 R32 · Cheap Yellow Display · TTGO T-Display · Seeed XIAO ESP32-S3 · Arduino Nano ESP32 · Arduino Nano RP2040 Connect · Seeed XIAO RP2040 · Waveshare RP2040-Zero · Arduino Uno R4 WiFi ## The calls you will use In the order a sketch meets them. ### U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE) A 128x64 SSD1306 on the hardware I2C pins with a full 1 KB buffer and no reset pin. U8G2_R2 rotates it 180 degrees. ### u8g2.begin() Starts the bus and wakes the display. It does not clear the buffer for you. ### u8g2.clearBuffer() Clears the frame buffer in full buffer mode before drawing the next frame. ### u8g2.setFont(u8g2_font_ncenB08_tr) Chooses a font. The suffix says which characters it holds: _tr is the printable ASCII range, _tn numbers only, which saves flash. ### u8g2.drawStr(0, 10, "Hello") Draws a string with its baseline at y = 10. It takes text only; for numbers use setCursor() and print(). ### u8g2.drawFrame(0, 0, 128, 64) An outlined rectangle; drawBox() is the filled one, drawCircle() and drawDisc() the outlined and filled circles. ### u8g2.sendBuffer() Sends the full buffer to the display. Nothing appears in full buffer mode until this is called. ### u8g2.firstPage() Starts the page loop for the _1_ and _2_ constructors. All drawing goes inside the do-while, which runs once a page. ## Example: Hello World on an OLED with U8g2 On the Arduino Uno R3. It runs in the browser exactly as printed. sketch.ino · Arduino Uno R3 ### Wiring - Arduino Uno R3 A4 to OLED display, 128x64 SDA - Arduino Uno R3 A5 to OLED display, 128x64 SCL - Arduino Uno R3 5V to OLED display, 128x64 VCC - Arduino Uno R3 GND to OLED display, 128x64 GND Open it in the editor, wired and ready to run ## Common errors and how to fix them ### The screen shows noise or a picture shifted by two pixels The constructor names the wrong controller. Most 1.3 inch modules are SH1106, so use U8G2_SH1106_128X64_NONAME_F_HW_I2C; the 0.96 inch ones are usually SSD1306. ### Global variables use 95% of dynamic memory and the sketch misbehaves The _F_ constructor reserves 1 KB on an Uno. Switch to the _1_ or _2_ page buffer version and move the drawing into a firstPage() and nextPage() loop. ### drawStr() prints nothing for a number drawStr() expects a C string. Use setCursor() with print(), which formats numbers like Serial, or build the text with snprintf() first. ### Nothing is drawn although the code runs In full buffer mode sendBuffer() is missing; in page mode the drawing calls sit outside the do-while loop. Either way nothing reaches the panel. ## Questions and answers ### Do the U8g2 fonts look the same on Mokxi? Every u8g2_font name builds and sets a size, but Mokxi draws its own 5x8 characters scaled to the nearest whole size, not U8g2’s typefaces. Positions follow your sketch, so layout carries over to the real display. ## Keep going ### Learn - Arduino OLED Display (SSD1306) Tutorial - Arduino Nokia 5110 LCD: Wiring, Contrast and Code ### Parts - OLED display, 128x64 - OLED display, 128x32 - OLED display, 1.3 inch SH1106 - OLED display, 1.12 inch SH1107 - Nokia 5110 display, PCD8544 ### More displays libraries - Adafruit SSD1306 - Adafruit GFX Library - LiquidCrystal I2C - LiquidCrystal - LCD_I2C - hd44780 - TFT_eSPI - U8glib Every built-in library · Open the editor ## Try U8g2 without installing anything Open the example, change the sketch, and keep your version in a free account. Start building free Open the editor