JarCastingJava SSD1306 library
Java library for controlling SSD1306-based OLED display (usually the 0.96" mini OLEDs). It's not exactly the fastest thing, but it works quite well.
Based on Adafruit_Python_SSD1306.
You'll need Pi4J library.
Build a JAR file with maven
You need Maven to use the following procedure. Perform the following in the project root folder.
- Create the JAR file with the following command:
mvn clean package - Start example:
sudo java -classpath .:/opt/pi4j/lib/'*' -jar target/ssd1306-0.0.1-SNAPSHOT.jar
This will execute class Pixels which tries to draw a sample image via SPI on the OLED. In case you want to try the I2C bus version (PixelsI2c), execute the following command:
sudo java -classpath .:./target/ssd1306-0.0.1-SNAPSHOT.jar:/opt/pi4j/lib/'*' eu.ondryaso.ssd1306.examples.PixelsI2c
For performance reasons, it is advised to build the JAR on a PC and copy the file afterwards to the Raspberry PI. In case the commands are executed from the same folder where the JAR is located, the target/ has to be omitted.
Connecting
You just have to connect your display to the Raspberry Pi SPI (or I2C) pins. I haven't got the I2C thus I don't know if it'll work. Probably not. Reset pin is not always present and it's not necessary for function. You can use this website for reference.
SPI connection:
| Board pin name | Physical RPi pin | RPi pin name | WiringPi pin |
|---|---|---|---|
| DC | 16 | GPIO23 | 4 |
| CS | 24 | GPIO8, CE0 | 10 |
| MOSI/Data | 19 | GPIO10, MOSI | 12 |
| RST | 22 | GPIO22 | 3 |
| CLK | 23 | GPIO11, SCKL | 14 |
| GND | 6, 9, 20, 25 | Ground | |
| VCC/3V3 | 1 | 3V3 |
I2C connection:
| Board pin name | Physical RPi pin | RPi pin name | WiringPi pin |
|---|---|---|---|
| RST | 22 | GPIO22 | 3 |
| SDA | 3 | GPIO2, SDA | 8 |
| SCL | 5 | GPIO3, SCL | 9 |
| GND | 6, 9, 20, 25 | Ground | |
| VCC/3V3 | 1 | 3V3 |
Remember that Pi4J is using WiringPi numbering.
Usage
There are JavaDoc comments in the Display class itself, it should be pretty simple. Also, you can look to the examples.