3 ## OLED Supported Hardware
5 128x32 OLED modules using SSD1306 driver IC over I2C. Supported on AVR based keyboards. Possible but untested hardware includes ARM based keyboards and other sized OLED modules using SSD1306 over I2C, such as 128x64.
7 !> Warning: This OLED Driver currently uses the new i2c_master driver from split common code. If your split keyboard uses i2c to communication 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.
11 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.:
14 OLED_DRIVER_ENABLE = yes
17 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:
20 #ifdef OLED_DRIVER_ENABLE
21 void oled_task_user(void) {
22 // Host Keyboard Layer Status
23 oled_write_P(PSTR("Layer: "), false);
24 switch (biton32(layer_state)) {
26 oled_write_P(PSTR("Default\n"), false);
29 oled_write_P(PSTR("FN\n"), false);
32 oled_write_P(PSTR("ADJ\n"), false);
35 // Or use the write_ln shortcut over adding '\n' to the end of your string
36 oled_write_ln_P(PSTR("Undefined"), false);
39 // Host Keyboard LED Status
40 uint8_t led_usb_state = host_keyboard_leds();
41 oled_write_P(led_usb_state & (1<<USB_LED_NUM_LOCK) ? PSTR("NUMLCK ") : PSTR(" "), false);
42 oled_write_P(led_usb_state & (1<<USB_LED_CAPS_LOCK) ? PSTR("CAPLCK ") : PSTR(" "), false);
43 oled_write_P(led_usb_state & (1<<USB_LED_SCROLL_LOCK) ? PSTR("SCRLCK ") : PSTR(" "), false);
50 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:
53 static void render_logo(void) {
54 static const char PROGMEM qmk_logo[] = {
55 0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,0x90,0x91,0x92,0x93,0x94,
56 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,0xb0,0xb1,0xb2,0xb3,0xb4,
57 0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,0xd0,0xd1,0xd2,0xd3,0xd4,0};
59 oled_write_P(qmk_logo, false);
65 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:
68 #ifdef OLED_DRIVER_ENABLE
69 oled_rotation_t oled_init_user(oled_rotation_t rotation) {
70 if (!is_keyboard_master())
71 return OLED_ROTATION_180; // flips the display 180 degrees if offhand
75 void oled_task_user(void) {
76 if (is_keyboard_master()) {
77 render_status(); // Renders the current keyboard state (layer, lock, caps, scroll, etc)
79 render_logo(); // Renders a statuc logo
80 oled_scroll_left(); // Turns on scrolling
87 ## Basic Configuration
89 |Define |Default |Description |
90 |-----------------------|---------------|------------------------------------------------|
91 |`OLED_DISPLAY_ADDRESS` |`0x3C` |The i2c address of the OLED Display |
92 |`OLED_FONT_H` |`"glcdfont.c"` |The font code file to use for custom fonts |
93 |`OLED_FONT_START` |`0` |The starting characer index for custom fonts |
94 |`OLED_FONT_END` |`224` |The ending characer index for custom fonts |
95 |`OLED_FONT_WIDTH` |`6` |The font width |
96 |`OLED_FONT_HEIGHT` |`8` |The font height (untested) |
97 |`OLED_DISABLE_TIMEOUT` |*Not defined* |Disables the built in OLED timeout feature. Useful when implementing custom timeout rules.|
101 ## 128x64 & Custom sized OLED Displays
103 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.
105 |Define |Default |Description |
106 |-----------------------|---------------|-----------------------------------------------------------------|
107 |`OLED_DISPLAY_128X64` |*Not defined* |Changes the display defines for use with 128x64 displays. |
108 |`OLED_DISPLAY_CUSTOM` |*Not defined* |Changes the display defines for use with custom displays.<br />Requires user to implement the below defines. |
109 |`OLED_DISPLAY_WIDTH` |`128` |The width of the OLED display. |
110 |`OLED_DISPLAY_HEIGHT` |`32` |The height of the OLED display. |
111 |`OLED_MATRIX_SIZE` |`512` |The local buffer size to allocate.<br />`(OLED_DISPLAY_HEIGHT / 8 * OLED_DISPLAY_WIDTH)`. |
112 |`OLED_BLOCK_TYPE` |`uint16_t` |The unsigned integer type to use for dirty rendering. |
113 |`OLED_BLOCK_COUNT` |`16` |The number of blocks the display is divided into for dirty rendering.<br />`(sizeof(OLED_BLOCK_TYPE) * 8)`. |
114 |`OLED_BLOCK_SIZE` |`32` |The size of each block for dirty rendering<br />`(OLED_MATRIX_SIZE / OLED_BLOCK_COUNT)`. |
115 |`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`. |
116 |`OLED_SOURCE_MAP` |`{ 0, ... N }` |Precalculated source array to use for mapping source buffer to target OLED memory in 90 degree rendering. |
117 |`OLED_TARGET_MAP` |`{ 24, ... N }`|Precalculated target array to use for mapping source buffer to target OLED memory in 90 degree rendering. |
120 ### 90 Degree Rotation - Technical Mumbo Jumbo
123 // OLED Rotation enum values are flags
126 OLED_ROTATION_90 = 1,
127 OLED_ROTATION_180 = 2,
128 OLED_ROTATION_270 = 3, // OLED_ROTATION_90 | OLED_ROTATION_180
132 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.
134 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:
137 |---|---|---|---|---|---|
143 However the local buffer is stored as if it was Height x Width display instead of Width x Height, e.g:
146 |---|---|---|---|---|---|
152 So those precalculated arrays just index the memory offsets in the order in which each one iterates its data.
157 // OLED Rotation enum values are flags
160 OLED_ROTATION_90 = 1,
161 OLED_ROTATION_180 = 2,
162 OLED_ROTATION_270 = 3, // OLED_ROTATION_90 | OLED_ROTATION_180
165 // Initialize the OLED display, rotating the rendered output based on the define passed in.
166 // Returns true if the OLED was initialized successfully
167 bool oled_init(oled_rotation_t rotation);
169 // Called at the start of oled_init, weak function overridable by the user
170 // rotation - the value passed into oled_init
171 // Return new oled_rotation_t if you want to override default rotation
172 oled_rotation_t oled_init_user(oled_rotation_t rotation);
174 // Clears the display buffer, resets cursor position to 0, and sets the buffer to dirty for rendering
175 void oled_clear(void);
177 // Renders the dirty chunks of the buffer to OLED display
178 void oled_render(void);
180 // Moves cursor to character position indicated by column and line, wraps if out of bounds
181 // Max column denoted by 'oled_max_chars()' and max lines by 'oled_max_lines()' functions
182 void oled_set_cursor(uint8_t col, uint8_t line);
184 // Advances the cursor to the next page, writing ' ' if true
185 // Wraps to the begining when out of bounds
186 void oled_advance_page(bool clearPageRemainder);
188 // Moves the cursor forward 1 character length
189 // Advance page if there is not enough room for the next character
190 // Wraps to the begining when out of bounds
191 void oled_advance_char(void);
193 // Writes a single character to the buffer at current cursor position
194 // Advances the cursor while writing, inverts the pixels if true
195 // Main handler that writes character data to the display buffer
196 void oled_write_char(const char data, bool invert);
198 // Writes a string to the buffer at current cursor position
199 // Advances the cursor while writing, inverts the pixels if true
200 void oled_write(const char *data, bool invert);
202 // Writes a string to the buffer at current cursor position
203 // Advances the cursor while writing, inverts the pixels if true
204 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
205 void oled_write_ln(const char *data, bool invert);
207 // Writes a PROGMEM string to the buffer at current cursor position
208 // Advances the cursor while writing, inverts the pixels if true
209 // Remapped to call 'void oled_write(const char *data, bool invert);' on ARM
210 void oled_write_P(const char *data, bool invert);
212 // Writes a PROGMEM string to the buffer at current cursor position
213 // Advances the cursor while writing, inverts the pixels if true
214 // Advances the cursor to the next page, wiring ' ' to the remainder of the current page
215 // Remapped to call 'void oled_write_ln(const char *data, bool invert);' on ARM
216 void oled_write_ln_P(const char *data, bool invert);
218 // Can be used to manually turn on the screen if it is off
219 // Returns true if the screen was on or turns on
222 // Can be used to manually turn off the screen if it is on
223 // Returns true if the screen was off or turns off
226 // Basically it's oled_render, but with timeout management and oled_task_user calling!
227 void oled_task(void);
229 // Called at the start of oled_task, weak function overridable by the user
230 void oled_task_user(void);
232 // Scrolls the entire display right
233 // Returns true if the screen was scrolling or starts scrolling
234 // NOTE: display contents cannot be changed while scrolling
235 bool oled_scroll_right(void);
237 // Scrolls the entire display left
238 // Returns true if the screen was scrolling or starts scrolling
239 // NOTE: display contents cannot be changed while scrolling
240 bool oled_scroll_left(void);
242 // Turns off display scrolling
243 // Returns true if the screen was not scrolling or stops scrolling
244 bool oled_scroll_off(void);
246 // Returns the maximum number of characters that will fit on a line
247 uint8_t oled_max_chars(void);
249 // Returns the maximum number of lines that will fit on the OLED
250 uint8_t oled_max_lines(void);
253 ## SSD1306.h driver conversion guide
255 |Old API |Recommended New API |
256 |---------------------------|-----------------------------------|
257 |`struct CharacterMatrix` |*removed - delete all references* |
258 |`iota_gfx_init` |`oled_init` |
259 |`iota_gfx_on` |`oled_on` |
260 |`iota_gfx_off` |`oled_off` |
261 |`iota_gfx_flush` |`oled_render` |
262 |`iota_gfx_write_char` |`oled_write_char` |
263 |`iota_gfx_write` |`oled_write` |
264 |`iota_gfx_write_P` |`oled_write_P` |
265 |`iota_gfx_clear_screen` |`oled_clear` |
266 |`matrix_clear` |*removed - delete all references* |
267 |`matrix_write_char_inner` |`oled_write_char` |
268 |`matrix_write_char` |`oled_write_char` |
269 |`matrix_write` |`oled_write` |
270 |`matrix_write_ln` |`oled_write_ln` |
271 |`matrix_write_P` |`oled_write_P` |
272 |`matrix_write_ln_P` |`oled_write_ln_P` |
273 |`matrix_render` |`oled_render` |
274 |`iota_gfx_task` |`oled_task` |
275 |`iota_gfx_task_user` |`oled_task_user` |