Add ST7565 LCD driver (#13089)

Co-authored-by: Joakim Tufvegren <jocke@barbanet.com>

2 files changed, 694 insertions, 0 deletions

diff --git a/drivers/lcd/st7565.c b/drivers/lcd/st7565.c
new file mode 100644
index 0000000000..4b4891ce71
--- /dev/null
+++ b/drivers/lcd/st7565.c
@@ -0,0 +1,479 @@
+/*
+Copyright 2021
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "st7565.h"
+
+#include <string.h>
+
+#include "keyboard.h"
+#include "progmem.h"
+#include "timer.h"
+#include "wait.h"
+
+#include ST7565_FONT_H
+
+// Fundamental Commands
+#define CONTRAST 0x81
+#define DISPLAY_ALL_ON 0xA5
+#define DISPLAY_ALL_ON_RESUME 0xA4
+#define NORMAL_DISPLAY 0xA6
+#define DISPLAY_ON 0xAF
+#define DISPLAY_OFF 0xAE
+#define NOP 0xE3
+
+// Addressing Setting Commands
+#define PAM_SETCOLUMN_LSB 0x00
+#define PAM_SETCOLUMN_MSB 0x10
+#define PAM_PAGE_ADDR 0xB0  // 0xb0 -- 0xb7
+
+// Hardware Configuration Commands
+#define DISPLAY_START_LINE 0x40
+#define SEGMENT_REMAP 0xA0
+#define SEGMENT_REMAP_INV 0xA1
+#define COM_SCAN_INC 0xC0
+#define COM_SCAN_DEC 0xC8
+#define LCD_BIAS_7 0xA3
+#define LCD_BIAS_9 0xA2
+#define RESISTOR_RATIO 0x20
+#define POWER_CONTROL 0x28
+
+// Misc defines
+#ifndef ST7565_BLOCK_COUNT
+#    define ST7565_BLOCK_COUNT (sizeof(ST7565_BLOCK_TYPE) * 8)
+#endif
+#ifndef ST7565_BLOCK_SIZE
+#    define ST7565_BLOCK_SIZE (ST7565_MATRIX_SIZE / ST7565_BLOCK_COUNT)
+#endif
+
+#define ST7565_ALL_BLOCKS_MASK (((((ST7565_BLOCK_TYPE)1 << (ST7565_BLOCK_COUNT - 1)) - 1) << 1) | 1)
+
+#define HAS_FLAGS(bits, flags) ((bits & flags) == flags)
+
+// Display buffer's is the same as the display memory layout
+// this is so we don't end up with rounding errors with
+// parts of the display unusable or don't get cleared correctly
+// and also allows for drawing & inverting
+uint8_t            st7565_buffer[ST7565_MATRIX_SIZE];
+uint8_t *          st7565_cursor;
+ST7565_BLOCK_TYPE  st7565_dirty       = 0;
+bool               st7565_initialized = false;
+bool               st7565_active      = false;
+display_rotation_t st7565_rotation    = DISPLAY_ROTATION_0;
+#if ST7565_TIMEOUT > 0
+uint32_t st7565_timeout;
+#endif
+#if ST7565_UPDATE_INTERVAL > 0
+uint16_t st7565_update_timeout;
+#endif
+
+// Flips the rendering bits for a character at the current cursor position
+static void InvertCharacter(uint8_t *cursor) {
+    const uint8_t *end = cursor + ST7565_FONT_WIDTH;
+    while (cursor < end) {
+        *cursor = ~(*cursor);
+        cursor++;
+    }
+}
+
+bool st7565_init(display_rotation_t rotation) {
+    setPinOutput(ST7565_A0_PIN);
+    writePinHigh(ST7565_A0_PIN);
+    setPinOutput(ST7565_RST_PIN);
+    writePinHigh(ST7565_RST_PIN);
+
+    st7565_rotation = st7565_init_user(rotation);
+
+    spi_init();
+    spi_start(ST7565_SS_PIN, false, 0, ST7565_SPI_CLK_DIVISOR);
+
+    st7565_reset();
+
+    st7565_send_cmd(LCD_BIAS_7);
+    if (!HAS_FLAGS(st7565_rotation, DISPLAY_ROTATION_180)) {
+        st7565_send_cmd(SEGMENT_REMAP);
+        st7565_send_cmd(COM_SCAN_DEC);
+    } else {
+        st7565_send_cmd(SEGMENT_REMAP_INV);
+        st7565_send_cmd(COM_SCAN_INC);
+    }
+    st7565_send_cmd(DISPLAY_START_LINE | 0x00);
+    st7565_send_cmd(CONTRAST);
+    st7565_send_cmd(ST7565_CONTRAST);
+    st7565_send_cmd(RESISTOR_RATIO | 0x01);
+    st7565_send_cmd(POWER_CONTROL | 0x04);
+    wait_ms(50);
+    st7565_send_cmd(POWER_CONTROL | 0x06);
+    wait_ms(50);
+    st7565_send_cmd(POWER_CONTROL | 0x07);
+    wait_ms(10);
+    st7565_send_cmd(DISPLAY_ON);
+    st7565_send_cmd(DISPLAY_ALL_ON_RESUME);
+    st7565_send_cmd(NORMAL_DISPLAY);
+
+    spi_stop();
+
+#if ST7565_TIMEOUT > 0
+    st7565_timeout = timer_read32() + ST7565_TIMEOUT;
+#endif
+
+    st7565_clear();
+    st7565_initialized = true;
+    st7565_active      = true;
+    return true;
+}
+
+__attribute__((weak)) display_rotation_t st7565_init_user(display_rotation_t rotation) { return rotation; }
+
+void st7565_clear(void) {
+    memset(st7565_buffer, 0, sizeof(st7565_buffer));
+    st7565_cursor = &st7565_buffer[0];
+    st7565_dirty  = ST7565_ALL_BLOCKS_MASK;
+}
+
+uint8_t crot(uint8_t a, int8_t n) {
+    const uint8_t mask = 0x7;
+    n &= mask;
+    return a << n | a >> (-n & mask);
+}
+
+void st7565_render(void) {
+    if (!st7565_initialized) {
+        return;
+    }
+
+    // Do we have work to do?
+    st7565_dirty &= ST7565_ALL_BLOCKS_MASK;
+    if (!st7565_dirty) {
+        return;
+    }
+
+    // Find first dirty block
+    uint8_t update_start = 0;
+    while (!(st7565_dirty & ((ST7565_BLOCK_TYPE)1 << update_start))) {
+        ++update_start;
+    }
+
+    // Calculate commands to set memory addressing bounds.
+    uint8_t start_page   = ST7565_BLOCK_SIZE * update_start / ST7565_DISPLAY_WIDTH;
+    uint8_t start_column = ST7565_BLOCK_SIZE * update_start % ST7565_DISPLAY_WIDTH;
+    // IC has 132 segment drivers, for panels with less width we need to offset the starting column
+    if (HAS_FLAGS(st7565_rotation, DISPLAY_ROTATION_180)) {
+        start_column += (132 - ST7565_DISPLAY_WIDTH);
+    }
+
+    spi_start(ST7565_SS_PIN, false, 0, ST7565_SPI_CLK_DIVISOR);
+
+    st7565_send_cmd(PAM_PAGE_ADDR | start_page);
+    st7565_send_cmd(PAM_SETCOLUMN_LSB | ((ST7565_COLUMN_OFFSET + start_column) & 0x0f));
+    st7565_send_cmd(PAM_SETCOLUMN_MSB | ((ST7565_COLUMN_OFFSET + start_column) >> 4 & 0x0f));
+
+    st7565_send_data(&st7565_buffer[ST7565_BLOCK_SIZE * update_start], ST7565_BLOCK_SIZE);
+
+    // Turn on display if it is off
+    st7565_on();
+
+    // Clear dirty flag
+    st7565_dirty &= ~((ST7565_BLOCK_TYPE)1 << update_start);
+}
+
+void st7565_set_cursor(uint8_t col, uint8_t line) {
+    uint16_t index = line * ST7565_DISPLAY_WIDTH + col * ST7565_FONT_WIDTH;
+
+    // Out of bounds?
+    if (index >= ST7565_MATRIX_SIZE) {
+        index = 0;
+    }
+
+    st7565_cursor = &st7565_buffer[index];
+}
+
+void st7565_advance_page(bool clearPageRemainder) {
+    uint16_t index     = st7565_cursor - &st7565_buffer[0];
+    uint8_t  remaining = ST7565_DISPLAY_WIDTH - (index % ST7565_DISPLAY_WIDTH);
+
+    if (clearPageRemainder) {
+        // Remaining Char count
+        remaining = remaining / ST7565_FONT_WIDTH;
+
+        // Write empty character until next line
+        while (remaining--) st7565_write_char(' ', false);
+    } else {
+        // Next page index out of bounds?
+        if (index + remaining >= ST7565_MATRIX_SIZE) {
+            index     = 0;
+            remaining = 0;
+        }
+
+        st7565_cursor = &st7565_buffer[index + remaining];
+    }
+}
+
+void st7565_advance_char(void) {
+    uint16_t nextIndex      = st7565_cursor - &st7565_buffer[0] + ST7565_FONT_WIDTH;
+    uint8_t  remainingSpace = ST7565_DISPLAY_WIDTH - (nextIndex % ST7565_DISPLAY_WIDTH);
+
+    // Do we have enough space on the current line for the next character
+    if (remainingSpace < ST7565_FONT_WIDTH) {
+        nextIndex += remainingSpace;
+    }
+
+    // Did we go out of bounds
+    if (nextIndex >= ST7565_MATRIX_SIZE) {
+        nextIndex = 0;
+    }
+
+    // Update cursor position
+    st7565_cursor = &st7565_buffer[nextIndex];
+}
+
+// Main handler that writes character data to the display buffer
+void st7565_write_char(const char data, bool invert) {
+    // Advance to the next line if newline
+    if (data == '\n') {
+        // Old source wrote ' ' until end of line...
+        st7565_advance_page(true);
+        return;
+    }
+
+    if (data == '\r') {
+        st7565_advance_page(false);
+        return;
+    }
+
+    // copy the current render buffer to check for dirty after
+    static uint8_t st7565_temp_buffer[ST7565_FONT_WIDTH];
+    memcpy(&st7565_temp_buffer, st7565_cursor, ST7565_FONT_WIDTH);
+
+    _Static_assert(sizeof(font) >= ((ST7565_FONT_END + 1 - ST7565_FONT_START) * ST7565_FONT_WIDTH), "ST7565_FONT_END references outside array");
+
+    // set the reder buffer data
+    uint8_t cast_data = (uint8_t)data;  // font based on unsigned type for index
+    if (cast_data < ST7565_FONT_START || cast_data > ST7565_FONT_END) {
+        memset(st7565_cursor, 0x00, ST7565_FONT_WIDTH);
+    } else {
+        const uint8_t *glyph = &font[(cast_data - ST7565_FONT_START) * ST7565_FONT_WIDTH];
+        memcpy_P(st7565_cursor, glyph, ST7565_FONT_WIDTH);
+    }
+
+    // Invert if needed
+    if (invert) {
+        InvertCharacter(st7565_cursor);
+    }
+
+    // Dirty check
+    if (memcmp(&st7565_temp_buffer, st7565_cursor, ST7565_FONT_WIDTH)) {
+        uint16_t index = st7565_cursor - &st7565_buffer[0];
+        st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << (index / ST7565_BLOCK_SIZE));
+        // Edgecase check if the written data spans the 2 chunks
+        st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << ((index + ST7565_FONT_WIDTH - 1) / ST7565_BLOCK_SIZE));
+    }
+
+    // Finally move to the next char
+    st7565_advance_char();
+}
+
+void st7565_write(const char *data, bool invert) {
+    const char *end = data + strlen(data);
+    while (data < end) {
+        st7565_write_char(*data, invert);
+        data++;
+    }
+}
+
+void st7565_write_ln(const char *data, bool invert) {
+    st7565_write(data, invert);
+    st7565_advance_page(true);
+}
+
+void st7565_pan(bool left) {
+    uint16_t i = 0;
+    for (uint16_t y = 0; y < ST7565_DISPLAY_HEIGHT / 8; y++) {
+        if (left) {
+            for (uint16_t x = 0; x < ST7565_DISPLAY_WIDTH - 1; x++) {
+                i                = y * ST7565_DISPLAY_WIDTH + x;
+                st7565_buffer[i] = st7565_buffer[i + 1];
+            }
+        } else {
+            for (uint16_t x = ST7565_DISPLAY_WIDTH - 1; x > 0; x--) {
+                i                = y * ST7565_DISPLAY_WIDTH + x;
+                st7565_buffer[i] = st7565_buffer[i - 1];
+            }
+        }
+    }
+    st7565_dirty = ST7565_ALL_BLOCKS_MASK;
+}
+
+display_buffer_reader_t st7565_read_raw(uint16_t start_index) {
+    if (start_index > ST7565_MATRIX_SIZE) start_index = ST7565_MATRIX_SIZE;
+    display_buffer_reader_t ret_reader;
+    ret_reader.current_element         = &st7565_buffer[start_index];
+    ret_reader.remaining_element_count = ST7565_MATRIX_SIZE - start_index;
+    return ret_reader;
+}
+
+void st7565_write_raw_byte(const char data, uint16_t index) {
+    if (index > ST7565_MATRIX_SIZE) index = ST7565_MATRIX_SIZE;
+    if (st7565_buffer[index] == data) return;
+    st7565_buffer[index] = data;
+    st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << (index / ST7565_BLOCK_SIZE));
+}
+
+void st7565_write_raw(const char *data, uint16_t size) {
+    uint16_t cursor_start_index = st7565_cursor - &st7565_buffer[0];
+    if ((size + cursor_start_index) > ST7565_MATRIX_SIZE) size = ST7565_MATRIX_SIZE - cursor_start_index;
+    for (uint16_t i = cursor_start_index; i < cursor_start_index + size; i++) {
+        if (st7565_buffer[i] == data[i]) continue;
+        st7565_buffer[i] = data[i];
+        st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << (i / ST7565_BLOCK_SIZE));
+    }
+}
+
+void st7565_write_pixel(uint8_t x, uint8_t y, bool on) {
+    if (x >= ST7565_DISPLAY_WIDTH) {
+        return;
+    }
+    uint16_t index = x + (y / 8) * ST7565_DISPLAY_WIDTH;
+    if (index >= ST7565_MATRIX_SIZE) {
+        return;
+    }
+    uint8_t data = st7565_buffer[index];
+    if (on) {
+        data |= (1 << (y % 8));
+    } else {
+        data &= ~(1 << (y % 8));
+    }
+    if (st7565_buffer[index] != data) {
+        st7565_buffer[index] = data;
+        st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << (index / ST7565_BLOCK_SIZE));
+    }
+}
+
+#if defined(__AVR__)
+void st7565_write_P(const char *data, bool invert) {
+    uint8_t c = pgm_read_byte(data);
+    while (c != 0) {
+        st7565_write_char(c, invert);
+        c = pgm_read_byte(++data);
+    }
+}
+
+void st7565_write_ln_P(const char *data, bool invert) {
+    st7565_write_P(data, invert);
+    st7565_advance_page(true);
+}
+
+void st7565_write_raw_P(const char *data, uint16_t size) {
+    uint16_t cursor_start_index = st7565_cursor - &st7565_buffer[0];
+    if ((size + cursor_start_index) > ST7565_MATRIX_SIZE) size = ST7565_MATRIX_SIZE - cursor_start_index;
+    for (uint16_t i = cursor_start_index; i < cursor_start_index + size; i++) {
+        uint8_t c = pgm_read_byte(data++);
+        if (st7565_buffer[i] == c) continue;
+        st7565_buffer[i] = c;
+        st7565_dirty |= ((ST7565_BLOCK_TYPE)1 << (i / ST7565_BLOCK_SIZE));
+    }
+}
+#endif  // defined(__AVR__)
+
+bool st7565_on(void) {
+    if (!st7565_initialized) {
+        return st7565_active;
+    }
+
+#if ST7565_TIMEOUT > 0
+    st7565_timeout = timer_read32() + ST7565_TIMEOUT;
+#endif
+
+    if (!st7565_active) {
+        spi_start(ST7565_SS_PIN, false, 0, ST7565_SPI_CLK_DIVISOR);
+        st7565_send_cmd(DISPLAY_ON);
+        spi_stop();
+        st7565_active = true;
+        st7565_on_user();
+    }
+    return st7565_active;
+}
+
+__attribute__((weak)) void st7565_on_user(void) {}
+
+bool st7565_off(void) {
+    if (!st7565_initialized) {
+        return !st7565_active;
+    }
+
+    if (st7565_active) {
+        spi_start(ST7565_SS_PIN, false, 0, ST7565_SPI_CLK_DIVISOR);
+        st7565_send_cmd(DISPLAY_OFF);
+        spi_stop();
+        st7565_active = false;
+        st7565_off_user();
+    }
+    return !st7565_active;
+}
+
+__attribute__((weak)) void st7565_off_user(void) {}
+
+bool st7565_is_on(void) { return st7565_active; }
+
+uint8_t st7565_max_chars(void) { return ST7565_DISPLAY_WIDTH / ST7565_FONT_WIDTH; }
+
+uint8_t st7565_max_lines(void) { return ST7565_DISPLAY_HEIGHT / ST7565_FONT_HEIGHT; }
+
+void st7565_task(void) {
+    if (!st7565_initialized) {
+        return;
+    }
+
+#if ST7565_UPDATE_INTERVAL > 0
+    if (timer_elapsed(st7565_update_timeout) >= ST7565_UPDATE_INTERVAL) {
+        st7565_update_timeout = timer_read();
+        st7565_set_cursor(0, 0);
+        st7565_task_user();
+    }
+#else
+    st7565_set_cursor(0, 0);
+    st7565_task_user();
+#endif
+
+    // Smart render system, no need to check for dirty
+    st7565_render();
+
+    // Display timeout check
+#if ST7565_TIMEOUT > 0
+    if (st7565_active && timer_expired32(timer_read32(), st7565_timeout)) {
+        st7565_off();
+    }
+#endif
+}
+
+__attribute__((weak)) void st7565_task_user(void) {}
+
+void st7565_reset(void) {
+    writePinLow(ST7565_RST_PIN);
+    wait_ms(20);
+    writePinHigh(ST7565_RST_PIN);
+    wait_ms(20);
+}
+
+spi_status_t st7565_send_cmd(uint8_t cmd) {
+    writePinLow(ST7565_A0_PIN);
+    return spi_write(cmd);
+}
+
+spi_status_t st7565_send_data(uint8_t *data, uint16_t length) {
+    writePinHigh(ST7565_A0_PIN);
+    return spi_transmit(data, length);
+}
diff --git a/drivers/lcd/st7565.h b/drivers/lcd/st7565.h
new file mode 100644
index 0000000000..53cfc9a810
--- /dev/null
+++ b/drivers/lcd/st7565.h
@@ -0,0 +1,215 @@
+/*
+Copyright 2021
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "spi_master.h"
+
+#ifndef ST7565_DISPLAY_WIDTH
+#    define ST7565_DISPLAY_WIDTH 128
+#endif
+#ifndef ST7565_DISPLAY_HEIGHT
+#    define ST7565_DISPLAY_HEIGHT 32
+#endif
+#ifndef ST7565_MATRIX_SIZE
+#    define ST7565_MATRIX_SIZE (ST7565_DISPLAY_HEIGHT / 8 * ST7565_DISPLAY_WIDTH)  // 1024 (compile time mathed)
+#endif
+#ifndef ST7565_BLOCK_TYPE
+#    define ST7565_BLOCK_TYPE uint16_t
+#endif
+#ifndef ST7565_BLOCK_COUNT
+#    define ST7565_BLOCK_COUNT (sizeof(ST7565_BLOCK_TYPE) * 8)  // 32 (compile time mathed)
+#endif
+#ifndef ST7565_BLOCK_SIZE
+#    define ST7565_BLOCK_SIZE (ST7565_MATRIX_SIZE / ST7565_BLOCK_COUNT)  // 32 (compile time mathed)
+#endif
+
+// the column address corresponding to the first column in the display hardware
+#if !defined(ST7565_COLUMN_OFFSET)
+#    define ST7565_COLUMN_OFFSET 0
+#endif
+
+// spi clock divisor
+#if !defined(ST7565_SPI_CLK_DIVISOR)
+#    define ST7565_SPI_CLK_DIVISOR 4
+#endif
+
+// Custom font file to use
+#if !defined(ST7565_FONT_H)
+#    define ST7565_FONT_H "glcdfont.c"
+#endif
+// unsigned char value of the first character in the font file
+#if !defined(ST7565_FONT_START)
+#    define ST7565_FONT_START 0
+#endif
+// unsigned char value of the last character in the font file
+#if !defined(ST7565_FONT_END)
+#    define ST7565_FONT_END 223
+#endif
+// Font render width
+#if !defined(ST7565_FONT_WIDTH)
+#    define ST7565_FONT_WIDTH 6
+#endif
+// Font render height
+#if !defined(ST7565_FONT_HEIGHT)
+#    define ST7565_FONT_HEIGHT 8
+#endif
+// Default contrast level
+#if !defined(ST7565_CONTRAST)
+#    define ST7565_CONTRAST 32
+#endif
+
+#if !defined(ST7565_TIMEOUT)
+#    if defined(ST7565_DISABLE_TIMEOUT)
+#        define ST7565_TIMEOUT 0
+#    else
+#        define ST7565_TIMEOUT 60000
+#    endif
+#endif
+
+#if !defined(ST7565_UPDATE_INTERVAL) && defined(SPLIT_KEYBOARD)
+#    define ST7565_UPDATE_INTERVAL 50
+#endif
+
+typedef struct __attribute__((__packed__)) {
+    uint8_t *current_element;
+    uint16_t remaining_element_count;
+} display_buffer_reader_t;
+
+// Rotation enum values are flags
+typedef enum { DISPLAY_ROTATION_0, DISPLAY_ROTATION_180 } display_rotation_t;
+
+// Initialize the display, rotating the rendered output based on the define passed in.
+// Returns true if the display was initialized successfully
+bool st7565_init(display_rotation_t rotation);
+
+// Called at the start of st7565_init, weak function overridable by the user
+// rotation - the value passed into st7565_init
+// Return new display_rotation_t if you want to override default rotation
+display_rotation_t st7565_init_user(display_rotation_t rotation);
+
+// Clears the display buffer, resets cursor position to 0, and sets the buffer to dirty for rendering
+void st7565_clear(void);
+
+// Renders the dirty chunks of the buffer to display
+void st7565_render(void);
+
+// Moves cursor to character position indicated by column and line, wraps if out of bounds
+// Max column denoted by 'st7565_max_chars()' and max lines by 'st7565_max_lines()' functions
+void st7565_set_cursor(uint8_t col, uint8_t line);
+
+// Advances the cursor to the next page, writing ' ' if true
+// Wraps to the begining when out of bounds
+void st7565_advance_page(bool clearPageRemainder);
+
+// Moves the cursor forward 1 character length
+// Advance page if there is not enough room for the next character
+// Wraps to the begining when out of bounds
+void st7565_advance_char(void);
+
+// Writes a single character to the buffer at current cursor position
+// Advances the cursor while writing, inverts the pixels if true
+// Main handler that writes character data to the display buffer
+void st7565_write_char(const char data, bool invert);
+
+// Writes a string to the buffer at current cursor position
+// Advances the cursor while writing, inverts the pixels if true
+void st7565_write(const char *data, bool invert);
+
+// Writes a string to the buffer at current cursor position
+// Advances the cursor while writing, inverts the pixels if true
+// Advances the cursor to the next page, wiring ' ' to the remainder of the current page
+void st7565_write_ln(const char *data, bool invert);
+
+// Pans the buffer to the right (or left by passing true) by moving contents of the buffer
+// Useful for moving the screen in preparation for new drawing
+void st7565_pan(bool left);
+
+// Returns a pointer to the requested start index in the buffer plus remaining
+// buffer length as struct
+display_buffer_reader_t st7565_read_raw(uint16_t start_index);
+
+// Writes a string to the buffer at current cursor position
+void st7565_write_raw(const char *data, uint16_t size);
+
+// Writes a single byte into the buffer at the specified index
+void st7565_write_raw_byte(const char data, uint16_t index);
+
+// Sets a specific pixel on or off
+// Coordinates start at top-left and go right and down for positive x and y
+void st7565_write_pixel(uint8_t x, uint8_t y, bool on);
+
+#if defined(__AVR__)
+// Writes a PROGMEM string to the buffer at current cursor position
+// Advances the cursor while writing, inverts the pixels if true
+// Remapped to call 'void st7565_write(const char *data, bool invert);' on ARM
+void st7565_write_P(const char *data, bool invert);
+
+// Writes a PROGMEM string to the buffer at current cursor position
+// Advances the cursor while writing, inverts the pixels if true
+// Advances the cursor to the next page, wiring ' ' to the remainder of the current page
+// Remapped to call 'void st7565_write_ln(const char *data, bool invert);' on ARM
+void st7565_write_ln_P(const char *data, bool invert);
+
+// Writes a PROGMEM string to the buffer at current cursor position
+void st7565_write_raw_P(const char *data, uint16_t size);
+#else
+#    define st7565_write_P(data, invert) st7565_write(data, invert)
+#    define st7565_write_ln_P(data, invert) st7565_write_ln(data, invert)
+#    define st7565_write_raw_P(data, size) st7565_write_raw(data, size)
+#endif  // defined(__AVR__)
+
+// Can be used to manually turn on the screen if it is off
+// Returns true if the screen was on or turns on
+bool st7565_on(void);
+
+// Called when st7565_on() turns on the screen, weak function overridable by the user
+// Not called if the screen is already on
+void st7565_on_user(void);
+
+// Can be used to manually turn off the screen if it is on
+// Returns true if the screen was off or turns off
+bool st7565_off(void);
+
+// Called when st7565_off() turns off the screen, weak function overridable by the user
+// Not called if the screen is already off
+void st7565_off_user(void);
+
+// Returns true if the screen is currently on, false if it is
+// not
+bool st7565_is_on(void);
+
+// Basically it's st7565_render, but with timeout management and st7565_task_user calling!
+void st7565_task(void);
+
+// Called at the start of st7565_task, weak function overridable by the user
+void st7565_task_user(void);
+
+// Returns the maximum number of characters that will fit on a line
+uint8_t st7565_max_chars(void);
+
+// Returns the maximum number of lines that will fit on the display
+uint8_t st7565_max_lines(void);
+
+void st7565_reset(void);
+
+spi_status_t st7565_send_cmd(uint8_t cmd);
+
+spi_status_t st7565_send_data(uint8_t *data, uint16_t length);