diff options
| -rw-r--r-- | include/driver/ssd1306.h | 79 | ||||
| -rw-r--r-- | src/driver/ssd1306.cc | 1 |
2 files changed, 77 insertions, 3 deletions
diff --git a/include/driver/ssd1306.h b/include/driver/ssd1306.h index 2afcb86..e439ca6 100644 --- a/include/driver/ssd1306.h +++ b/include/driver/ssd1306.h @@ -38,28 +38,101 @@ class SSD1306 { unsigned char txbuf[130]; unsigned char rxbuf[2]; + /* + * Adjust both SSD1306_SET_SEG_REMAP and SSD1306_SET_COM_OUT_DIR for + * 180° rotation. + */ const unsigned char init1[6] = { + // Turn off power for configuration SSD1306_SET_DISP | 0x00, + + /* + * Enable Horizontal Addressing Mode. Assuming image data is + * {A, B, C, ...}, each byte corresponds to a 1x8 column, starting + * at the top left corner and proceeding to the right and then down: + * + * A7 B7 C7 ... + * .. .. .. ... + * A0 B0 C0 ... + */ SSD1306_SET_MEM_ADDR, 0x00, + + // RAM line 0 == display line 0 SSD1306_SET_DISP_START_LINE | 0x00, + + /* + * Horizontal Layout: Column 127 is SEG0. + * This depends on the connection between SSD1306 and OLED. + * Use 0x00 if your content is horizontally mirrored. + */ SSD1306_SET_SEG_REMAP | 0x01, + + /* + * Multiplex ratio is the number of display lines + * (i.e., the display height) + */ SSD1306_SET_MUX_RATIO }; - // height + + // height-1 sent by init() + const unsigned char init2[4] = { + /* + * Vertical Layout: Scan from COM63 to COM0. + * This depends on the connection between SSD1306 and OLED. + * Use 0x00 if your content is vertically mirrored. + */ SSD1306_SET_COM_OUT_DIR | 0x08, + + // No vertical display offset SSD1306_SET_DISP_OFFSET, 0x00, + + /* + * COM PIN layout depends on display height and type. See + * datasheet and init(). + */ SSD1306_SET_COM_PIN_CFG }; + // height == 32? 0x02 : 0x12 + const unsigned char init3[13] = { + /* + * Set clock to recommended values: 370 kHz (bits 7..4), + * no divider (bits 3..0). Increase divider for glitchy effects. + * The datasheet is unclear on the clock frequency range. + */ SSD1306_SET_DISP_CLK_DIV, 0x80, - SSD1306_SET_PRECHARGE, 0xf1, + + /* + * Set line (multiplex) precharge times. + * phase 1 (discharge pixels to avoid effects from the previous line): 8 cycles + * phase 2 (charge pixels for next line): 8 cycles + * decrease phase 1 time for glitchy effects. + */ + SSD1306_SET_PRECHARGE, 0x88, + + /* + * VCOM deselect level. Unknown. + * 0x00: ~0.65 VCC + * 0x20: ~0.77 VCC + * 0x30: ~0.85 VCC + */ SSD1306_SET_VCOM_DESEL, 0x30, + + // start with medium contrast SSD1306_SET_CONTRAST, 0x7f, + + // display content == RAM content SSD1306_SET_ENTIRE_ON, - SSD1306_SET_NORM_INV, + + // regular (uninverted) display + SSD1306_SET_NORM_INV | 0x00, + + // Enable charge pump (provide power to the display) SSD1306_SET_CHARGE_PUMP, 0x14, + + // turn on display SSD1306_SET_DISP | 0x01 }; diff --git a/src/driver/ssd1306.cc b/src/driver/ssd1306.cc index 23b938d..cf36c13 100644 --- a/src/driver/ssd1306.cc +++ b/src/driver/ssd1306.cc @@ -20,6 +20,7 @@ void SSD1306::init() for (i = 0; i < sizeof(init1); i++) { writeCommand(init1[i]); } + // set multiplex ratio (i.e., number of rows) writeCommand(height - 1); for (i = 0; i < sizeof(init2); i++) { writeCommand(init2[i]); |