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gohaigohai
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IO: Add an OLED display example
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‎java/libraries/io/examples/I2CScreen/I2CScreen.pde‎

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import processing.io.*;
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// 0.96" 128x64 OLED display ("SKU 346540")
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SSD1306 oled;
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void setup() {
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size(128, 64);
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// the display can be set to one of these two addresses: 0x3c (default) or 0x3d
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// (they might be listed as 0x7a and 0x7b on the circuit board)
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oled = new SSD1306(I2C.list()[0], 0x3c);
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}
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void draw() {
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line(0, 0, 127, 63);
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line(0, 63, 127, 0);
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oled.sendImage(get());
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}

‎java/libraries/io/examples/I2CScreen/SSD1306.pde‎

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import processing.io.I2C;
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// SSD1306 is a small, inexpensive 128x64 pixels monochrome OLED display
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// available online as "0.96" 128x64 OLED display", SKU 346540
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// or from Adafruit
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// datasheet: https://www.adafruit.com/datasheets/SSD1306.pdf
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class SSD1306 extends I2C {
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int address;
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// there can be more than one device connected to the bus
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// as long as they have different addresses
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SSD1306(String dev, int address) {
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super(dev);
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this.address = address;
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init();
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}
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protected void init() {
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writeCommand(0xae); // turn display off
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writeCommand(0xa8, 0x3f); // set multiplex ratio to the highest setting
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writeCommand(0x8d, 0x14); // enable charge pump
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writeCommand(0x20, 0x00); // set memory addressing mode to horizontal
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writeCommand(0xd5, 0x80); // set display clock divide ratio & oscillator frequency to default
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writeCommand(0xd3, 0x00); // no display offset
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writeCommand(0x40 | 0x00); // set default display start line
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// use the following two lines to flip the display
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writeCommand(0xa0 | 0x01); // set segment re-map
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writeCommand(0xc8); // set COM output scan direction
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writeCommand(0xda, 0x12); // set COM pins hardware configuration
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writeCommand(0xd9, 0xf1); // set pre-charge period to 241x DCLK
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writeCommand(0xdB, 0x40); // set VCOMH deselect level
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writeCommand(0xa4); // display RAM content (not all-on)
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writeCommand(0xa6); // set normal (not-inverted) display
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// set this since we don't have access to the OLED's reset pins (?)
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writeCommand(0x21, 0, 127); // set column address
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writeCommand(0x22, 0, 7); // set page address
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writeCommand(0x81, 0xcf); // set contrast
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writeCommand(0x2e); // deactivate scroll
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writeCommand(0xaf); // turn display on
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}
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void invert(boolean inverted) {
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if (inverted) {
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writeCommand(0xa7);
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} else {
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writeCommand(0xa6);
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}
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}
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void sendImage(PImage img) {
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sendImage(img, 0, 0);
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}
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void sendImage(PImage img, int startX, int startY) {
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byte[] frame = new byte[1024];
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img.loadPixels();
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for (int y=startY; y < height && y-startY < 64; y++) {
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for (int x=startX; x < width && x-startX < 128; x++) {
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if (brightness(img.pixels[y*img.width+x]) < 128) {
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// this isn't the normal (scanline) mapping, but 8 pixels below each other at a time
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// white pixels have their bit turned on
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frame[x + (y/8)*128] |= (1 << (y % 8));
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}
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}
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}
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sendFramebuffer(frame);
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}
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void sendFramebuffer(byte[] buf) {
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if (buf.length != 1024) {
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System.err.println("The framebuffer should be 1024 bytes long, with one bit per pixel");
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throw new IllegalArgumentException("Unexpected buffer size");
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}
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writeCommand(0x00 | 0x0); // set start address
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writeCommand(0x10 | 0x0); // set higher column start address
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writeCommand(0x40 | 0x0); // set start line
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// send the frame buffer as 16 byte long packets
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for (int i=0; i < buf.length/16; i++) {
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super.beginTransmission(address);
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super.write(0x40); // indicates data write
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for (int j=0; j < 16; j++) {
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super.write(buf[i*16+j]);
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}
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super.endTransmission();
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}
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}
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protected void writeCommand(int arg1) {
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super.beginTransmission(address);
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super.write(0x00); // indicates command write
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super.write(arg1);
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super.endTransmission();
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}
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protected void writeCommand(int arg1, int arg2) {
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super.beginTransmission(address);
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super.write(0x00);
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super.write(arg1);
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super.write(arg2);
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super.endTransmission();
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}
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protected void writeCommand(int arg1, int arg2, int arg3) {
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super.beginTransmission(address);
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super.write(0x00);
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super.write(arg1);
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super.write(arg2);
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super.write(arg3);
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super.endTransmission();
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}
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}

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