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This is a quick tutorial for our 128x64 and 128x32 pixel monochrome OLED displays. These displays are small, only about 1" diameter, but very readable due to the high contrast of an OLED display. Each OLED display is made of 128x64 or 128x32 individual white OLEDs, each one is turned on or off by the controller chip. Because the display makes its own light, no backlight is required. This reduces the power required to run the OLED and is why the display has such high contrast; we really like this miniature display for its crispness!

The driver chip, SSD1306 can communicate in multiple ways including I2C, SPI and 8-bit parallel. However, only the 128x64 display has all these interfaces available. For the 128x32 OLED, only SPI is available. Frankly, we prefer SPI since its the most flexible and uses a small number of I/O pins so our example code and wiring diagram will use that.

The OLED and driver require a 3.3V power supply and 3.3V logic levels for communication. The power requirements depend a little on how much of the display is lit but on average the display uses about 20mA from the 3.3V supply. Built into the OLED driver is a simple switch-cap charge pump that turns 3.3v-5v into a high voltage drive for the OLEDs. You can run the entire display off of one 3.3V supply or use 3.3V for the chip power and up to 4.5V for the OLED charge pump or 3.3V for the chip power and a 7-9V supply directly into the OLED high voltage pin.

• VDD is the 3.3V logic power. This must be 3 or 3.3V
• VBAT is the input to the charge pump. If you use the charge pump, this must be 3.3V to 4.2V
• VCC is the high voltage OLED pin. If you're using the internal charge pump, this must be left unconnected. If you're not using the charge pump, connect this to a 7-9V DC power supply.

For most users, we suggest connecting VDD and VBAT together to 3.3V and then leaving VCC unconnected

The OLED runs at 3.3V so you'll need to use a level shifting chip to use with a 5V microcontroller. The following will assume that is the case. If you're running a 3.3V microcontroller system, you can skip the level shifter.

We'll assume you want to use this in a breadboard, take a piece of 0.1" header 10 pins long

Place the header in a breadboard and then place the left hand side of the OLED on top

And solder the pins

We'll be using the internal charge pump so connect VDD and VBAT together (they will connect to 3.3V). GND goes to ground

Place a CD4050 level shifter chip so pin one is at the top

Connect pin 10 to D/C pin 12 to CLK (SPI clock) and pin 15 to DAT (SPI data)

Connect pin 2 to RES (reset) and pin 4 to CS (chip select). Pin 1 goes to 3.3V and pin 8 to ground.

You can connect the inputs of the level shifter to any pins you want but in this case we connected digital I/O 13 to pin 3 of the level shifter, 12 to pin 5, 11 to pin 9, 10 to pin 11 and 9 to pin 14. This matches the example code we have written. Once you get this working, you can try another set of pins.

Download and install our Arduino library. If you're using another system, its pretty simple to adapt our code, the interface we use is basic bit-twiddling SPI.

Load the example sketch to demonstrate the capabilities of the library and display.

You can create bitmaps to display easily with the LCD assistant software. First make your image using any kind of graphics software such as photoshop or Paint and save as a Monochrome Bitmap (bmp)

Select the following options:

and import your monochrome bitmap image. Save the output to a cpp file

You can use the output directly with our example code

You can download our SSD1306 OLED display Arduino library from github which comes with example code. The library can print text, bitmaps, pixels, rectangles, circles and lines. It uses 1K of RAM since it needs to buffer the entire display but its very fast! The code is simple to adapt to any other microcontroller.

UG-2864HSWEG01 Datasheet

UG-2864HSWEG01 User Guide

SSD1306 Datasheet