Initialize display cmd

[TimonPeng]

Why initialize display cmd is big difference from with the previous repo and u8g2 too. Where does it come from?

https://github.com/adafruit/Adafruit_CircuitPython_SSD1306/blob/main/adafruit_ssd1306.py#L116

# self.poweron
0xAE | 0x01

# self.init_display
0xAE,  # off
# address setting
0x20,
0x10  # Page Addressing Mode
if self.page_addressing
else 0x00,  # Horizontal Addressing Mode
# resolution and layout
0x40,
0xA0 | 0x01,  # column addr 127 mapped to SEG0
0xA8,
self.height - 1,
0xC0 | 0x08,  # scan from COM[N] to COM0
0xD3,
0x00,
0xDA,
0x02 if self.width > 2 * self.height else 0x12,
# timing and driving scheme
0xD5,
0x80,
0xD9,
0x22 if self.external_vcc else 0xF1,
0xDB,
0x30,  # 0.83*Vcc  # n.b. specs for ssd1306 64x32 oled screens imply this should be 0x40
# display
0x81,
0xFF,  # maximum
0xA4,  # output follows RAM contents
0xA6,  # not inverted
0xAD,
0x30,  # enable internal IREF during display on
# charge pump
0x8D,
0x10 if self.external_vcc else 0x14,
0xAE | 0x01,  # display on

https://github.com/adafruit/micropython-adafruit-ssd1306/blob/master/ssd1306.py#L40

# self.init_display
0xAE | 0x00,  # off
# address setting
0x20, 0x00,  # horizontal
# resolution and layout
0x40 | 0x00,
0xA0 | 0x01,  # column addr 127 mapped to SEG0
0xA8, self.height - 1,
0xC0 | 0x08,  # scan from COM[N] to COM0
0xD3, 0x00,
0xDA, 0x02 if self.height == 32 else 0x12,
# timing and driving scheme
0xD5, 0x80,
0xD9, 0x22 if self.external_vcc else 0xF1,
0xDB, 0x30,  # 0.83*Vcc
# display
0x81, 0xFF,  # maximum
0xA4,  # output follows RAM contents
0xA6,  # not inverted
# charge pump
0x8D, 0x10 if self.external_vcc else 0x14,
0xAE | 0x01  # on

https://github.com/adafruit/Adafruit_CircuitPython_DisplayIO_SSD1306/blob/main/adafruit_displayio_ssd1306.py#L43

_INIT_SEQUENCE = (
    b"\xAE\x00"  # DISPLAY_OFF
    b"\x20\x01\x00"  # Set memory addressing to horizontal mode.
    b"\x81\x01\xcf"  # set contrast control
    b"\xA1\x00"  # Column 127 is segment 0
    b"\xA6\x00"  # Normal display
    b"\xc8\x00"  # Normal display
    b"\xA8\x01\x3f"  # Mux ratio is 1/64
    b"\xd5\x01\x80"  # Set divide ratio
    b"\xd9\x01\xf1"  # Set pre-charge period
    b"\xda\x01\x12"  # Set com configuration
    b"\xdb\x01\x40"  # Set vcom configuration
    b"\x8d\x01\x14"  # Enable charge pump
    b"\xAF\x00"  # DISPLAY_ON
)

https://github.com/adafruit/Adafruit_SSD1306/blob/master/Adafruit_SSD1306.cpp#L564

  // Init sequence
  static const uint8_t PROGMEM init1[] = {SSD1306_DISPLAYOFF,         // 0xAE
                                          SSD1306_SETDISPLAYCLOCKDIV, // 0xD5
                                          0x80, // the suggested ratio 0x80
                                          SSD1306_SETMULTIPLEX}; // 0xA8
  ssd1306_commandList(init1, sizeof(init1));
  ssd1306_command1(HEIGHT - 1);

  static const uint8_t PROGMEM init2[] = {SSD1306_SETDISPLAYOFFSET, // 0xD3
                                          0x0,                      // no offset
                                          SSD1306_SETSTARTLINE | 0x0, // line #0
                                          SSD1306_CHARGEPUMP};        // 0x8D
  ssd1306_commandList(init2, sizeof(init2));

  ssd1306_command1((vccstate == SSD1306_EXTERNALVCC) ? 0x10 : 0x14);

  static const uint8_t PROGMEM init3[] = {SSD1306_MEMORYMODE, // 0x20
                                          0x00, // 0x0 act like ks0108
                                          SSD1306_SEGREMAP | 0x1,
                                          SSD1306_COMSCANDEC};
  ssd1306_commandList(init3, sizeof(init3));

  uint8_t comPins = 0x02;
  contrast = 0x8F;

  if ((WIDTH == 128) && (HEIGHT == 32)) {
    comPins = 0x02;
    contrast = 0x8F;
  } else if ((WIDTH == 128) && (HEIGHT == 64)) {
    comPins = 0x12;
    contrast = (vccstate == SSD1306_EXTERNALVCC) ? 0x9F : 0xCF;
  } else if ((WIDTH == 96) && (HEIGHT == 16)) {
    comPins = 0x2; // ada x12
    contrast = (vccstate == SSD1306_EXTERNALVCC) ? 0x10 : 0xAF;
  } else {
    // Other screen varieties -- TBD
  }

  ssd1306_command1(SSD1306_SETCOMPINS);
  ssd1306_command1(comPins);
  ssd1306_command1(SSD1306_SETCONTRAST);
  ssd1306_command1(contrast);

  ssd1306_command1(SSD1306_SETPRECHARGE); // 0xd9
  ssd1306_command1((vccstate == SSD1306_EXTERNALVCC) ? 0x22 : 0xF1);
  static const uint8_t PROGMEM init5[] = {
      SSD1306_SETVCOMDETECT, // 0xDB
      0x40,
      SSD1306_DISPLAYALLON_RESUME, // 0xA4
      SSD1306_NORMALDISPLAY,       // 0xA6
      SSD1306_DEACTIVATE_SCROLL,
      SSD1306_DISPLAYON}; // Main screen turn on
  ssd1306_commandList(init5, sizeof(init5));

  TRANSACTION_END

[TimonPeng]

Theoretically the ssd1309 is partially compatible with the ssd1306, but the different drivers above show different results and I would like to know what the standard is..

[markbirss]

@TimonPeng

I found and used this other driver with my SDD1309 Display
https://github.com/smittytone/SSD1306OLED-Python