ssd1306_driver.h

/*
 * ssd1306_driver.h
 *
 *  Created on: Apr 19, 2025
 *      Author: johnm
 *
 *  This and related files contains driver code displaying simple scrollable text
 *  messages onto 128x64 OLED screens controlled by SSD1306 drivers (e.g. DFR0650).
 */
 
#ifndef SRC_DEVICE_OLED_SSD1306_DRIVER_H_
#define SRC_DEVICE_OLED_SSD1306_DRIVER_H_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include "cmsis_os.h"
#include "i2c.h"
#include "stdint.h"
#include "stdlib.h"
#include "stm32f4xx_hal.h"
#include "string.h"
 
#define OLED_ADDRESS 0x78
#define OLED_WIDTH 128
#define OLED_HEIGHT 64
#define CHAR_WIDTH 6   // 5x7 + 1 spacing
#define CHAR_HEIGHT 8  // 8 pixels per page
#define MAX_ROWS (OLED_HEIGHT / CHAR_HEIGHT)
#define MAX_COLS (OLED_WIDTH / CHAR_WIDTH)
 
extern I2C_HandleTypeDef hi2c2;
 
#define I2C_DEVICE hi2c2
 
typedef struct {
    uint8_t buffer[MAX_ROWS][OLED_WIDTH];
} Display_t;
 
// Message_t data type for outputting messages onto the OLED display.
// newline characters in title field will be replaced with spaces.
// title and body fields will "scroll" horizontally and vertically respectively
// if they are too long for their display areas.
typedef struct {
    const char* title;
    const char* body;
} Message_t;
 
int get_line_start_index(const char* msg, uint8_t line);
uint8_t get_line_count(const char* msg);
 
void ssd1306_send_command(uint8_t command);
void ssd1306_send_data(uint8_t* data, size_t size);
 
void ssd1306_init();
void ssd1306_clear(void);
void ssd1306_write_char_to_buffer(Display_t* display, char c,
                                  uint8_t cursor_row, uint8_t cursor_col);
void ssd1306_write_title(Display_t* display, Message_t message, uint8_t offset);
void ssd1306_write_body(Display_t* display, Message_t message,
                        uint8_t line_start);
void ssd1306_write_buffer_to_gddram(Display_t* display);
 
#ifdef __cplusplus
}
#endif
 
#endif /* SRC_DEVICE_OLED_SSD1306_DRIVER_H_ */