docs/feature_oled_driver.md

   1 # OLED Driver
   2
   3 ## OLED Supported Hardware
   4
   5 OLED modules using SSD1306 or SH1106 driver ICs, communicating over I2C.
   6 Tested combinations:
   7
   8 | IC driver |   Size | Keyboard Platform | Notes                    |
   9 |-----------|--------|-------------------|--------------------------|
  10 | SSD1306   | 128x32 | AVR               | Primary support          |
  11 | SSD1306   | 128x64 | AVR               | Verified working         |
  12 | SSD1306   | 128x32 | ARM               |                          |
  13 | SH1106    | 128x64 | AVR               | No rotation or scrolling |
  14
  15 Hardware configurations using ARM-based microcontrollers or different sizes of OLED modules may be compatible, but are untested.
  16
  17 !> Warning: This OLED Driver currently uses the new i2c_master driver from split common code. If your split keyboard uses I2C to communicate between sides, this driver could cause an address conflict (serial is fine). Please contact your keyboard vendor and ask them to migrate to the latest split common code to fix this. In addition, the display timeout system to reduce OLED burn-in also uses split common to detect keypresses, so you will need to implement custom timeout logic for non-split common keyboards.
  18
  19 ## Usage
  20
  21 To enable the OLED feature, there are three steps. First, when compiling your keyboard, you'll need to set `OLED_DRIVER_ENABLE=yes` in `rules.mk`, e.g.:
  22
  23 ```
  24 OLED_DRIVER_ENABLE = yes
  25 ```
  26
  27 This enables the feature and the `OLED_DRIVER_ENABLE` define. Then in your `keymap.c` file, you will need to implement the user task call, e.g:
  28
  29 ```C++
  30 #ifdef OLED_DRIVER_ENABLE
  31 void oled_task_user(void) {
  32   // Host Keyboard Layer Status
  33   oled_write_P(PSTR("Layer: "), false);
  34   switch (get_highest_layer(layer_state)) {
  35     case _QWERTY:
  36       oled_write_P(PSTR("Default\n"), false);
  37       break;
  38     case _FN:
  39       oled_write_P(PSTR("FN\n"), false);
  40       break;
  41     case _ADJ:
  42       oled_write_P(PSTR("ADJ\n"), false);
  43       break;
  44     default:
  45       // Or use the write_ln shortcut over adding '\n' to the end of your string
  46       oled_write_ln_P(PSTR("Undefined"), false);
  47   }
  48
  49   // Host Keyboard LED Status
  50   uint8_t led_usb_state = host_keyboard_leds();
  51   oled_write_P(led_usb_state & (1<<USB_LED_NUM_LOCK) ? PSTR("NUMLCK ") : PSTR("       "), false);
  52   oled_write_P(led_usb_state & (1<<USB_LED_CAPS_LOCK) ? PSTR("CAPLCK ") : PSTR("       "), false);
  53   oled_write_P(led_usb_state & (1<<USB_LED_SCROLL_LOCK) ? PSTR("SCRLCK ") : PSTR("       "), false);
  54 }
  55 #endif
  56 ```
  57
  58 ## Logo Example
  59
  60 In the default font, ranges in the font file are reserved for a QMK Logo. To Render this logo to the oled screen, use the following code example:
  61
  62 ```C++
  63 static void render_logo(void) {
  64   static const char PROGMEM qmk_logo[] = {
  65     0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,0x90,0x91,0x92,0x93,0x94,
  66     0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,0xb0,0xb1,0xb2,0xb3,0xb4,
  67     0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,0xd0,0xd1,0xd2,0xd3,0xd4,0};
  68
  69   oled_write_P(qmk_logo, false);
  70 }
  71 ```
  72
  73 ## Other Examples
  74
  75 In split keyboards, it is very common to have two OLED displays that each render different content and oriented flipped differently. You can do this by switching which content to render by using the return from `is_keyboard_master()` or `is_keyboard_left()` found in `split_util.h`, e.g:
  76
  77 ```C++
  78 #ifdef OLED_DRIVER_ENABLE
  79 oled_rotation_t oled_init_user(oled_rotation_t rotation) {
  80   if (!is_keyboard_master())
  81     return OLED_ROTATION_180;  // flips the display 180 degrees if offhand
  82   return rotation;
  83 }
  84
  85 void oled_task_user(void) {
  86   if (is_keyboard_master()) {
  87     render_status();     // Renders the current keyboard state (layer, lock, caps, scroll, etc)
  88   } else {
  89     render_logo();       // Renders a statuc logo
  90     oled_scroll_left();  // Turns on scrolling
  91   }
  92 }
  93 #endif
  94 ```
  95
  96
  97  ## Basic Configuration
  98
  99 | Define                     | Default           | Description                                                                                                                |
 100 |----------------------------|-------------------|----------------------------------------------------------------------------------------------------------------------------|
 101 | `OLED_DISPLAY_ADDRESS`     | `0x3C`            | The i2c address of the OLED Display                                                                                        |
 102 | `OLED_FONT_H`              | `"glcdfont.c"`    | The font code file to use for custom fonts                                                                                 |
 103 | `OLED_FONT_START`          | `0`               | The starting characer index for custom fonts                                                                               |
 104 | `OLED_FONT_END`            | `224`             | The ending characer index for custom fonts                                                                                 |
 105 | `OLED_FONT_WIDTH`          | `6`               | The font width                                                                                                             |
 106 | `OLED_FONT_HEIGHT`         | `8`               | The font height (untested)                                                                                                 |
 107 | `OLED_TIMEOUT`             | `60000`           | Turns off the OLED screen after 60000ms of keyboard inactivity. Helps reduce OLED Burn-in. Set to 0 to disable.            |
 108 | `OLED_SCROLL_TIMEOUT`      | `0`               | Scrolls the OLED screen after 0ms of OLED inactivity. Helps reduce OLED Burn-in. Set to 0 to disable.                      |
 109 | `OLED_SCROLL_TIMEOUT_RIGHT`| *Not defined*     | Scroll timeout direction is right when defined, left when undefined.                                                       |
 110 | `OLED_IC`                  | `OLED_IC_SSD1306` | Set to `OLED_IC_SH1106` if you're using the SH1106 OLED controller.                                                        |
 111 | `OLED_COLUMN_OFFSET`       | `0`               | (SH1106 only.) Shift output to the right this many pixels.<br />Useful for 128x64 displays centered on a 132x64 SH1106 IC. |
 112
 113  ## 128x64 & Custom sized OLED Displays
 114
 115  The default display size for this feature is 128x32 and all necessary defines are precalculated with that in mind. We have added a define, `OLED_DISPLAY_128X64`, to switch all the values to be used in a 128x64 display, as well as added a custom define, `OLED_DISPLAY_CUSTOM`, that allows you to provide the necessary values to the driver.
 116
 117 |Define                 |Default        |Description                                                      |
 118 |-----------------------|---------------|-----------------------------------------------------------------|
 119 |`OLED_DISPLAY_128X64`  |*Not defined*  |Changes the display defines for use with 128x64 displays.        |
 120 |`OLED_DISPLAY_CUSTOM`  |*Not defined*  |Changes the display defines for use with custom displays.<br />Requires user to implement the below defines. |
 121 |`OLED_DISPLAY_WIDTH`   |`128`          |The width of the OLED display.                                   |
 122 |`OLED_DISPLAY_HEIGHT`  |`32`           |The height of the OLED display.                                  |
 123 |`OLED_MATRIX_SIZE`     |`512`          |The local buffer size to allocate.<br />`(OLED_DISPLAY_HEIGHT / 8 * OLED_DISPLAY_WIDTH)`. |
 124 |`OLED_BLOCK_TYPE`      |`uint16_t`     |The unsigned integer type to use for dirty rendering. |
 125 |`OLED_BLOCK_COUNT`     |`16`           |The number of blocks the display is divided into for dirty rendering.<br />`(sizeof(OLED_BLOCK_TYPE) * 8)`. |
 126 |`OLED_BLOCK_SIZE`      |`32`           |The size of each block for dirty rendering<br />`(OLED_MATRIX_SIZE / OLED_BLOCK_COUNT)`. |
 127 |`OLED_COM_PINS`        |`COM_PINS_SEQ` |How the SSD1306 chip maps it's memory to display.<br />Options are `COM_PINS_SEQ`, `COM_PINS_ALT`, `COM_PINS_SEQ_LR`, & `COM_PINS_ALT_LR`. |
 128 |`OLED_SOURCE_MAP`      |`{ 0, ... N }` |Precalculated source array to use for mapping source buffer to target OLED memory in 90 degree rendering.         |
 129 |`OLED_TARGET_MAP`      |`{ 24, ... N }`|Precalculated target array to use for mapping source buffer to target OLED memory in 90 degree rendering.         |
 130
 131
 132 ### 90 Degree Rotation - Technical Mumbo Jumbo
 133
 134 !> Rotation is unsupported on the SH1106.
 135
 136 ```C
 137 // OLED Rotation enum values are flags
 138 typedef enum {
 139     OLED_ROTATION_0   = 0,
 140     OLED_ROTATION_90  = 1,
 141     OLED_ROTATION_180 = 2,
 142     OLED_ROTATION_270 = 3, // OLED_ROTATION_90 | OLED_ROTATION_180
 143 } oled_rotation_t;
 144 ```
 145
 146  OLED displays driven by SSD1306 drivers only natively support in hard ware 0 degree and 180 degree rendering. This feature is done in software and not free. Using this feature will increase the time to calculate what data to send over i2c to the OLED. If you are strapped for cycles, this can cause keycodes to not register. In testing however, the rendering time on an `atmega32u4` board only went from 2ms to 5ms and keycodes not registering was only noticed once we hit 15ms.
 147
 148  90 Degree Rotated Rendering is achieved by using bitwise operations to rotate each 8 block of memory and uses two precalculated arrays to remap buffer memory to OLED memory. The memory map defines are precalculated for remap performance and are calculated based on the OLED Height, Width, and Block Size. For example, in the 128x32 implementation with a `uint8_t` block type, we have a 64 byte block size. This gives us eight 8 byte blocks that need to be rotated and rendered. The OLED renders horizontally two 8 byte blocks before moving down a page, e.g:
 149
 150 |   |   |   |   |   |   |
 151 |---|---|---|---|---|---|
 152 | 0 | 1 |   |   |   |   |
 153 | 2 | 3 |   |   |   |   |
 154 | 4 | 5 |   |   |   |   |
 155 | 6 | 7 |   |   |   |   |
 156
 157 However the local buffer is stored as if it was Height x Width display instead of Width x Height, e.g:
 158
 159 |   |   |   |   |   |   |
 160 |---|---|---|---|---|---|
 161 | 3 | 7 |   |   |   |   |
 162 | 2 | 6 |   |   |   |   |
 163 | 1 | 5 |   |   |   |   |
 164 | 0 | 4 |   |   |   |   |
 165
 166 So those precalculated arrays just index the memory offsets in the order in which each one iterates its data.
 167
 168 ## OLED API
 169
 170 ```C++
 171 // OLED Rotation enum values are flags
 172 typedef enum {
 173     OLED_ROTATION_0   = 0,
 174     OLED_ROTATION_90  = 1,
 175     OLED_ROTATION_180 = 2,
 176     OLED_ROTATION_270 = 3, // OLED_ROTATION_90 | OLED_ROTATION_180
 177 } oled_rotation_t;
 178
 179 // Initialize the OLED display, rotating the rendered output based on the define passed in.
 180 // Returns true if the OLED was initialized successfully
 181 bool oled_init(oled_rotation_t rotation);
 182
 183 // Called at the start of oled_init, weak function overridable by the user
 184 // rotation - the value passed into oled_init
 185 // Return new oled_rotation_t if you want to override default rotation
 186 oled_rotation_t oled_init_user(oled_rotation_t rotation);
 187
 188 // Clears the display buffer, resets cursor position to 0, and sets the buffer to dirty for rendering
 189 void oled_clear(void);
 190
 191 // Renders the dirty chunks of the buffer to OLED display
 192 void oled_render(void);
 193
 194 // Moves cursor to character position indicated by column and line, wraps if out of bounds
 195 // Max column denoted by 'oled_max_chars()' and max lines by 'oled_max_lines()' functions
 196 void oled_set_cursor(uint8_t col, uint8_t line);
 197
 198 // Advances the cursor to the next page, writing ' ' if true
 199 // Wraps to the begining when out of bounds
 200 void oled_advance_page(bool clearPageRemainder);
 201
 202 // Moves the cursor forward 1 character length
 203 // Advance page if there is not enough room for the next character
 204 // Wraps to the begining when out of bounds
 205 void oled_advance_char(void);
 206
 207 // Writes a single character to the buffer at current cursor position
 208 // Advances the cursor while writing, inverts the pixels if true
 209 // Main handler that writes character data to the display buffer
 210 void oled_write_char(const char data, bool invert);
 211
 212 // Writes a string to the buffer at current cursor position
 213 // Advances the cursor while writing, inverts the pixels if true
 214 void oled_write(const char *data, bool invert);
 215
 216 // Writes a string to the buffer at current cursor position
 217 // Advances the cursor while writing, inverts the pixels if true
 218 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
 219 void oled_write_ln(const char *data, bool invert);
 220
 221 // Writes a PROGMEM string to the buffer at current cursor position
 222 // Advances the cursor while writing, inverts the pixels if true
 223 // Remapped to call 'void oled_write(const char *data, bool invert);' on ARM
 224 void oled_write_P(const char *data, bool invert);
 225
 226 // Writes a PROGMEM string to the buffer at current cursor position
 227 // Advances the cursor while writing, inverts the pixels if true
 228 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
 229 // Remapped to call 'void oled_write_ln(const char *data, bool invert);' on ARM
 230 void oled_write_ln_P(const char *data, bool invert);
 231
 232 // Can be used to manually turn on the screen if it is off
 233 // Returns true if the screen was on or turns on
 234 bool oled_on(void);
 235
 236 // Can be used to manually turn off the screen if it is on
 237 // Returns true if the screen was off or turns off
 238 bool oled_off(void);
 239
 240 // Basically it's oled_render, but with timeout management and oled_task_user calling!
 241 void oled_task(void);
 242
 243 // Called at the start of oled_task, weak function overridable by the user
 244 void oled_task_user(void);
 245
 246 // Scrolls the entire display right
 247 // Returns true if the screen was scrolling or starts scrolling
 248 // NOTE: display contents cannot be changed while scrolling
 249 bool oled_scroll_right(void);
 250
 251 // Scrolls the entire display left
 252 // Returns true if the screen was scrolling or starts scrolling
 253 // NOTE: display contents cannot be changed while scrolling
 254 bool oled_scroll_left(void);
 255
 256 // Turns off display scrolling
 257 // Returns true if the screen was not scrolling or stops scrolling
 258 bool oled_scroll_off(void);
 259
 260 // Returns the maximum number of characters that will fit on a line
 261 uint8_t oled_max_chars(void);
 262
 263 // Returns the maximum number of lines that will fit on the OLED
 264 uint8_t oled_max_lines(void);
 265 ```
 266
 267 !> Scrolling and rotation are unsupported on the SH1106.
 268
 269 ## SSD1306.h driver conversion guide
 270
 271 |Old API                    |Recommended New API                |
 272 |---------------------------|-----------------------------------|
 273 |`struct CharacterMatrix`   |*removed - delete all references*  |
 274 |`iota_gfx_init`            |`oled_init`                        |
 275 |`iota_gfx_on`              |`oled_on`                          |
 276 |`iota_gfx_off`             |`oled_off`                         |
 277 |`iota_gfx_flush`           |`oled_render`                      |
 278 |`iota_gfx_write_char`      |`oled_write_char`                  |
 279 |`iota_gfx_write`           |`oled_write`                       |
 280 |`iota_gfx_write_P`         |`oled_write_P`                     |
 281 |`iota_gfx_clear_screen`    |`oled_clear`                       |
 282 |`matrix_clear`             |*removed - delete all references*  |
 283 |`matrix_write_char_inner`  |`oled_write_char`                  |
 284 |`matrix_write_char`        |`oled_write_char`                  |
 285 |`matrix_write`             |`oled_write`                       |
 286 |`matrix_write_ln`          |`oled_write_ln`                    |
 287 |`matrix_write_P`           |`oled_write_P`                     |
 288 |`matrix_write_ln_P`        |`oled_write_ln_P`                  |
 289 |`matrix_render`            |`oled_render`                      |
 290 |`iota_gfx_task`            |`oled_task`                        |
 291 |`iota_gfx_task_user`       |`oled_task_user`                   |