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Thread: Project with 2 SSD1106/SSD1306 I2C-OLED on Teensy 3.6

  1. #1
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    Project with 2 SSD1106/SSD1306 I2C-OLED on Teensy 3.6

    It works on the teensy 3.6 without Pullup-Resistors. Perhaps they are inside the OLED-Baords.
    I use 2 cheap OLED-Boards with 4 Pins each, GND, VCC, SCL and SCA.
    Both use the same I2C-Address but they use different I2C-Ports.

    I thought that it is much more complex, but finally it was very easy to do.

    Here is the code that works fine:


    Code:
    /**************************************************************************
    Example to connect 2 I2C SSD1106-OLEDs to Teensy 3.6
    Both OLEDs have the same size in my case 128x64 Pixels
     **************************************************************************/
    
    #include <SPI.h>
    #include <Wire.h>
    #include <Adafruit_GFX.h>
    #include <Adafruit_SSD1306.h>
    
    #define SCREEN_WIDTH 128 // OLED display width, in pixels
    #define SCREEN_HEIGHT 64 // OLED display height, in pixels
    
    // Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
    #define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
    
    // Display 0 on PINs 18/19
    Adafruit_SSD1306 dp0(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
    // Display 1 on Pins 37/38
    Adafruit_SSD1306 dp1(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire1, OLED_RESET);
    
    void setup() {
      Serial.begin(9600);
      
      // Perhaps these lines are not needed, I have only tested with these
      Wire.setSDA(15);
      Wire.setSCL(19);
      Wire1.setSDA(37);
      Wire1.setSCL(38);
    
      if(!dp1.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
        Serial.println(F("SSD1306 Display1 allocation failed"));
        for(;;); // Don't proceed, loop forever
      }
      
      // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
      if(!dp0.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
        Serial.println(F("SSD1306 Display 0 allocation failed"));
        for(;;); // Don't proceed, loop forever
      }
    
      // Show initial display buffer contents on the screen --
      // the library initializes this with an Adafruit splash screen.
      dp0.display();
      delay(200); // Pause for 2 seconds
      dp0.clearDisplay();
    
      dp1.display();
      delay(200); // Pause for 2 seconds
      // Clear the buffer
      dp1.clearDisplay();
    
    delay(1000);
    
      // Draw a single pixel in white
      dp0.drawPixel(10, 10, WHITE);
      dp1.drawPixel(10, 10, WHITE);
    
      // Show the display buffer on the screen. You MUST call display() after
      // drawing commands to make them visible on screen!
      dp0.display();
      dp1.display();
      delay(200);
      // display.display() is NOT necessary after every single drawing command,
      // unless that's what you want...rather, you can batch up a bunch of
      // drawing operations and then update the screen all at once by calling
      // display.display(). These examples demonstrate both approaches...
    
    
      testdrawchar();      // Draw characters of the default font
    
      testdrawstyles();    // Draw 'stylized' characters
    
      dp0.clearDisplay();
      dp1.clearDisplay();
    }
    
    void loop() {
    }
    
    
    void testdrawchar(void) {
      dp0.clearDisplay();
      dp0.setTextSize(1);      // Normal 1:1 pixel scale
      dp0.setTextSize(1);      // Normal 1:1 pixel scale
      dp0.setTextColor(WHITE); // Draw white text
      dp0.setCursor(0, 0);     // Start at top-left corner
      dp0.cp437(true);         // Use full 256 char 'Code Page 437' font
    
      // Not all the characters will fit on the display. This is normal.
      // Library will draw what it can and the rest will be clipped.
      for(int16_t i=0; i<256; i++) {
        if(i == '\n') dp0.write(' ');
        else          dp0.write(i);
      }
    
      dp0.display();
      delay(20);
    
      dp1.clearDisplay();
      dp1.setTextSize(1);      // Normal 1:1 pixel scale
      dp1.setTextSize(1);      // Normal 1:1 pixel scale
      dp1.setTextColor(WHITE); // Draw white text
      dp1.setCursor(0, 0);     // Start at top-left corner
      dp1.cp437(true);         // Use full 256 char 'Code Page 437' font
    
      // Not all the characters will fit on the display. This is normal.
      // Library will draw what it can and the rest will be clipped.
      for(int16_t i=0; i<256; i++) {
        if(i == '\n') dp1.write(' ');
        else          dp1.write(i);
      }
    
      dp1.display();
      delay(200);
    
    }
    
    void testdrawstyles(void) {
    
      // Change Display 0
      dp0.clearDisplay();
    
      dp0.setTextSize(1);             // Normal 1:1 pixel scale
      dp0.setTextColor(WHITE);        // Draw white text
      dp0.setCursor(0,0);             // Start at top-left corner
      dp0.println(F("Display 0 works!"));
    
      dp0.setTextColor(BLACK, WHITE); // Draw 'inverse' text
      dp0.println(3.141592);
    
      dp0.setTextSize(2);             // Draw 2X-scale text
      dp0.setTextColor(WHITE);
      dp0.print(F("0x")); 
      dp0.println(0xDEADBEEF, HEX);
    
      dp0.display();
      delay(200);
    
    
      // Same on Display 1
      dp1.clearDisplay();
    
      dp1.setTextSize(1);             // Normal 1:1 pixel scale
      dp1.setTextColor(WHITE);        // Draw white text
      dp1.setCursor(0,0);             // Start at top-left corner
      dp1.println(F("Display 1 works!"));
    
      dp1.setTextColor(BLACK, WHITE); // Draw 'inverse' text
      dp1.println(3.141592);
    
      dp1.setTextSize(2);             // Draw 2X-scale text
      dp1.setTextColor(WHITE);
      dp1.print(F("0x")); 
      dp1.println(0xDEADBEEF, HEX);
    
      dp1.display();
      delay(2000);
      
    }
    /*
    void testdrawpot1(void) {
      // draw outer ring
      dp0.
      // draw marker on pot
      dp0.
      
    }
    */
    I dropped the code here because there where no running examples with code available.
    Perhaps add this to the examples.
    Last edited by Erich; 08-11-2019 at 08:41 PM.

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