Derzeit gibt es günstige OLED Displays mit einer Auflösung von 128×64 Pixeln. Diese gibt es in zwei Grössen: 0,96” und 1,3” und werden vom gleiche Controller gesteueret, dem SSD1306. Bei einigen Anbietern gibt es diese OLED mit zwei Farben, wobei ein Viertel des Displays in einer Farbe und die anderen 3/4 in einer zweiten Farbe gehalten ist. Die Farbzuordnung ist fest und kann in einer Applikation recht nett genutzt werden.

Die I2C Addresse ist festgelegt auf 0x3c, wobei auch OLEDs mit 0x3d zu finden sind.

Um das Display zu betreiben benötigt man zwei Libraries von Adafruit:

• Adafruit_SSD1306
• Adafrui_GFX

Die Displays funktionieren auch gut mit der u8glib.

Der Anschluss des Displays an den HelvePic32 erfolgt über den herausgeführten I2C Bus:

Der Democode ist mit dem Adruino-Code identisch.

/*********************************************************************
 * This is an example for our Monochrome OLEDs based on SSD1306 drivers
 * 
 * Pick one up today in the adafruit shop!
 * ------> http://www.adafruit.com/category/63_98
 * 
 * This example is for a 128x64 size display using I2C to communicate
 * 3 pins are required to interface (2 I2C and one reset)
 * 
 * Adafruit invests time and resources providing this open source code, 
 * please support Adafruit and open-source hardware by purchasing 
 * products from Adafruit!
 * 
 * Written by Limor Fried/Ladyada  for Adafruit Industries.  
 * BSD license, check license.txt for more information
 * All text above, and the splash screen must be included in any redistribution
 *********************************************************************/
 
#include 
#include 
#include 
#include 
 
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);
 
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
 
 
#define LOGO16_GLCD_HEIGHT 16 
#define LOGO16_GLCD_WIDTH  16 
static const unsigned char PROGMEM logo16_glcd_bmp[] =
{ 
        B00000000, B11000000,
        B00000001, B11000000,
        B00000001, B11000000,
        B00000011, B11100000,
        B11110011, B11100000,
        B11111110, B11111000,
        B01111110, B11111111,
        B00110011, B10011111,
        B00011111, B11111100,
        B00001101, B01110000,
        B00011011, B10100000,
        B00111111, B11100000,
        B00111111, B11110000,
        B01111100, B11110000,
        B01110000, B01110000,
        B00000000, B00110000 };
 
#if (SSD1306_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif
 
void setup()   {                
        Serial.begin(9600);
 
        // by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
        display.begin(SSD1306_SWITCHCAPVCC, 0x3c);  // initialize with the I2C addr 0x3D (for the 128x64)
        // init done
 
        display.display(); // show splashscreen
        delay(2000);
        display.clearDisplay();   // clears the screen and buffer
 
        // draw a single pixel
        display.drawPixel(10, 10, WHITE);
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw many lines
        testdrawline();
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw rectangles
        testdrawrect();
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw multiple rectangles
        testfillrect();
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw mulitple circles
        testdrawcircle();
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw a white circle, 10 pixel radius
        display.fillCircle(display.width()/2, display.height()/2, 10, WHITE);
        display.display();
        delay(2000);
        display.clearDisplay();
 
        testdrawroundrect();
        delay(2000);
        display.clearDisplay();
 
        testfillroundrect();
        delay(2000);
        display.clearDisplay();
 
        testdrawtriangle();
        delay(2000);
        display.clearDisplay();
 
        testfilltriangle();
        delay(2000);
        display.clearDisplay();
 
        // draw the first ~12 characters in the font
        testdrawchar();
        display.display();
        delay(2000);
        display.clearDisplay();
 
        // draw scrolling text
        testscrolltext();
        delay(2000);
        display.clearDisplay();
 
        // text display tests
        display.setTextSize(1);
        display.setTextColor(WHITE);
        display.setCursor(0,0);
        display.println("Hello, world!");
        display.setTextColor(BLACK, WHITE); // 'inverted' text
        display.println(3.141592);
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.print("0x"); 
        display.println(0xDEADBEEF, HEX);
        display.display();
        delay(2000);
 
        // miniature bitmap display
        display.clearDisplay();
        display.drawBitmap(30, 16,  logo16_glcd_bmp, 16, 16, 1);
        display.display();
 
        // invert the display
        display.invertDisplay(true);
        delay(1000); 
        display.invertDisplay(false);
        delay(1000); 
 
        // draw a bitmap icon and 'animate' movement
        testdrawbitmap(logo16_glcd_bmp, LOGO16_GLCD_HEIGHT, LOGO16_GLCD_WIDTH);
}
 
 
void loop() {
 
}
 
 
void testdrawbitmap(const uint8_t *bitmap, uint8_t w, uint8_t h) {
        uint8_t icons[NUMFLAKES][3];
 
        // initialize
        for (uint8_t f=0; f< NUMFLAKES; f++) {
                icons[f][XPOS] = random(display.width());
                icons[f][YPOS] = 0;
                icons[f][DELTAY] = random(5) + 1;
 
                Serial.print("x: ");
                Serial.print(icons[f][XPOS], DEC);
                Serial.print(" y: ");
                Serial.print(icons[f][YPOS], DEC);
                Serial.print(" dy: ");
                Serial.println(icons[f][DELTAY], DEC);
        }
 
        while (1) {
                // draw each icon
                for (uint8_t f=0; f< NUMFLAKES; f++) {
                        display.drawBitmap(icons[f][XPOS], icons[f][YPOS], logo16_glcd_bmp, w, h, WHITE);
                }
                display.display();
                delay(200);
 
                // then erase it + move it
                for (uint8_t f=0; f< NUMFLAKES; f++) {
                        display.drawBitmap(icons[f][XPOS], icons[f][YPOS],  logo16_glcd_bmp, w, h, BLACK);
                        // move it
                        icons[f][YPOS] += icons[f][DELTAY];
                        // if its gone, reinit
                        if (icons[f][YPOS] > display.height()) {
                                icons[f][XPOS] = random(display.width());
                                icons[f][YPOS] = 0;
                                icons[f][DELTAY] = random(5) + 1;
                        }
                }
        }
}
 
 
void testdrawchar(void) {
        display.setTextSize(1);
        display.setTextColor(WHITE);
        display.setCursor(0,0);
 
        for (uint8_t i=0; i < 168; i++) {
                if (i == '\n') continue;
                display.write(i);
                if ((i > 0) && (i % 21 == 0))
                        display.println();
        }    
        display.display();
}
 
void testdrawcircle(void) {
        for (int16_t i=0; i<display.height(); i+=2) {
                display.drawCircle(display.width()/2, display.height()/2, i, WHITE);
        }
        display.display();
}
 
void testfillrect(void) {
        uint8_t color = 1;
        for (int16_t i=0; i<display.height()/2; i+=3) {
                // alternate colors
                display.fillRect(i, i, display.width()-i*2, display.height()-i*2, color%2);
                color++;
        }
        display.display();
}
 
void testdrawtriangle(void) {
        for (int16_t i=0; i<min(display.width(),display.height())/2; i+=5) {
                display.drawTriangle(display.width()/2, display.height()/2-i,
                display.width()/2-i, display.height()/2+i,
                display.width()/2+i, display.height()/2+i, WHITE);
        }
        display.display();
}
 
void testfilltriangle(void) {
        uint8_t color = WHITE;
        for (int16_t i=min(display.width(),display.height())/2; i>0; i-=5) {
                display.fillTriangle(display.width()/2, display.height()/2-i,
                display.width()/2-i, display.height()/2+i,
                display.width()/2+i, display.height()/2+i, WHITE);
                if (color == WHITE) color = BLACK;
                else color = WHITE;
        }
        display.display();
}
 
void testdrawroundrect(void) {
        for (int16_t i=0; i<display.height()/2-2; i+=2) {
                display.drawRoundRect(i, i, display.width()-2*i, display.height()-2*i, display.height()/4, WHITE);
        }
        display.display();
}
 
void testfillroundrect(void) {
        uint8_t color = WHITE;
        for (int16_t i=0; i<display.height()/2-2; i+=2) {
                display.fillRoundRect(i, i, display.width()-2*i, display.height()-2*i, display.height()/4, color);
                if (color == WHITE) color = BLACK;
                else color = WHITE;
        }
        display.display();
}
 
void testdrawrect(void) {
        for (int16_t i=0; i<display.height()/2; i+=2) {
                display.drawRect(i, i, display.width()-2*i, display.height()-2*i, WHITE);
        }
        display.display();
}
 
void testdrawline() {  
        for (int16_t i=0; i<display.width(); i+=4) {
                display.drawLine(0, 0, i, display.height()-1, WHITE);
        }
        display.display();
        for (int16_t i=0; i<display.height(); i+=4) {
                display.drawLine(0, 0, display.width()-1, i, WHITE);
        }
        display.display();
        delay(250);
 
        display.clearDisplay();
        for (int16_t i=0; i<display.width(); i+=4) {
                display.drawLine(0, display.height()-1, i, 0, WHITE);
        }
        display.display();
        for (int16_t i=display.height()-1; i>=0; i-=4) {
                display.drawLine(0, display.height()-1, display.width()-1, i, WHITE);
        }
        display.display();
        delay(250);
 
        display.clearDisplay();
        for (int16_t i=display.width()-1; i>=0; i-=4) {
                display.drawLine(display.width()-1, display.height()-1, i, 0, WHITE);
        }
        display.display();
        for (int16_t i=display.height()-1; i>=0; i-=4) {
                display.drawLine(display.width()-1, display.height()-1, 0, i, WHITE);
        }
        display.display();
        delay(250);
 
        display.clearDisplay();
        for (int16_t i=0; i<display.height(); i+=4) {
                display.drawLine(display.width()-1, 0, 0, i, WHITE);
        }
        display.display();
        for (int16_t i=0; i<display.width(); i+=4) {
                display.drawLine(display.width()-1, 0, i, display.height()-1, WHITE); 
        }
        display.display();
        delay(250);
}
 
void testscrolltext(void) {
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(10,0);
        display.clearDisplay();
        display.println("scroll");
        display.display();
 
        display.startscrollright(0x00, 0x0F);
        delay(2000);
        display.stopscroll();
        delay(1000);
        display.startscrollleft(0x00, 0x0F);
        delay(2000);
        display.stopscroll();
        delay(1000);    
        display.startscrolldiagright(0x00, 0x07);
        delay(2000);
        display.startscrolldiagleft(0x00, 0x07);
        delay(2000);
        display.stopscroll();
}

⇒HelvePic32