I2C-Controlled OLED Example¶

This example demonstrates how to interface a small 128x64 OLED module with the KNEO Pi using the I2C protocol.

The OLED module used in this example is a 128x64 display driven by the SSD1306 controller, which is commonly used in many low-resolution I2C-based displays.

Important

The chosen module is for demonstration purposes only; we do not promote or provide purchasing information for specific hardware.
The example provided below is specifically tailored for this controller and may not work with modules using different controllers.

The example code is sourced from the repository: ssd1306_linux .
This implementation utilizes Linux i2c-dev interface and requires no modification to work on the KNEO Pi.

Hardware Connection¶

Connect the I2C OLED module to the KNEO Pi as follows:

Module Pin	KNEO Pi Pin	Function
GND	GND / `pin-9`	Ground
VCC	3.3V / `pin-1`	Power Supply
SCK	I2C_0 SCL / `pin-5`	I2C Clock
SDA	I2C_0 SDA / `pin-3`	I2C Data

Info

This example uses the i2c-0 bus for communication

Running the Example¶

Clone the repository and navigate to the project directory:

git clone https://github.com/kneron/kneopi-examples.git
cd kneopi-examples
cd peripherals/C/i2c_oled

Build the example using the provided Makefile:

make

Run the example with the following command:

init the OLED once
- resolution 128x64
```
./ssd1306_bin -I 128x64
```

clear display

clear 1st line
```
./ssd1306_bin -c0
```
clear 4th line
```
./ssd1306_bin -c3
```
clear whole screen
```
./ssd1306_bin -c
```

display on/off
- turn off display
```
./ssd1306_bin -d 0
```
- turn on display
```
./ssd1306_bin -d 1
```
inverting display
- normal OLED (0 is off, 1 is on)
```
./ssd1306_bin -i 0
```
- invert OLED (0 is on, 1 is off)
```
./ssd1306_bin -i 1
```
print words
- write line "Hello World"
```
./ssd1306_bin -l "Hello World"
```
- write message "alpha\nbravo\ncharlie\ndelta" (please place \n for next line)
```
./ssd1306_bin -m "alpha\nbravo\ncharlie\ndelta"
```
I2C device address (default is /dev/i2c-0)
- using /dev/i2c-0
```
./ssd1306_bin -n 0
```
rotate display
- normal orientation
```
./ssd1306_bin -r 0
```
- turn 180 orientation
```
./ssd1306_bin -r 180
```
set cursor location
- set XY cursor 8,1(x is column, 8 columns skipping, y is row, 2nd line)
```
./ssd1306_bin -x 8 -y 1
```

Additional Information

For detailed usage and further customization, please refer to the official guide at ssd1306_linux github repository .