#ifndef INC_LCD_H_
#define INC_LCD_H_

#include "main.h"
#include "string.h"

// I2C LCD 4-bit 통신
#define I2C_LCD_ADDRESS			(0x27 << 1)
#define BACKLIGHT_ON			0x08

// LCD Command
#define DISPLAY_ON				0x0C
#define DISPLAY_OFF				0x08
#define CLEAR_DISPLAY			0x01	// delay 2ms 필요
#define RETURN_HOME				0x02

void lcdCommand(uint8_t command);
void lcdData(uint8_t data);
void i2cLCD_Init();
void lcdString(char *str);
void moveCursor(uint8_t row, uint8_t col);

#endif /* INC_LCD_H_ */

// lcd.c
#include "lcd.h"

extern I2C_HandleTypeDef hi2c1;

void lcdCommand(uint8_t command) {
	uint8_t high_nibble, low_nibble;
	uint8_t i2c_buffer[4];

	high_nibble = command & 0xf0;
	low_nibble = (command << 4) & 0xf0;

	i2c_buffer[0] = high_nibble | 0x04 | 0x08;		// en = 1, rs = 0, rw = 0, backlight = 1
	i2c_buffer[1] = high_nibble | 0x00 | 0x08;		// en = 0, rs = 0, rw = 0, backlight = 1
	i2c_buffer[2] = low_nibble  | 0x04 | 0x08;		// en = 1, rs = 0, rw = 0, backlight = 1
	i2c_buffer[3] = low_nibble  | 0x00 | 0x08;		// en = 0, rs = 0, rw = 0, backlight = 1

	while (HAL_I2C_Master_Transmit(&hi2c1, I2C_LCD_ADDRESS, i2c_buffer, 4, 100) != HAL_OK);
}

void lcdData(uint8_t data) {
	uint8_t high_nibble, low_nibble;
	uint8_t i2c_buffer[4];

	high_nibble = data & 0xf0;
	low_nibble = (data << 4) & 0xf0;

	i2c_buffer[0] = high_nibble | 0x05 | 0x08;
	i2c_buffer[1] = high_nibble | 0x01 | 0x08;
	i2c_buffer[2] = low_nibble  | 0x05 | 0x08;
	i2c_buffer[3] = low_nibble  | 0x01 | 0x08;

	while(HAL_I2C_Master_Transmit(&hi2c1, I2C_LCD_ADDRESS, i2c_buffer, 4, 100) != HAL_OK);
}

void i2cLCD_Init() {
	HAL_Delay(50);
	lcdCommand(0x33);
	HAL_Delay(5);
	lcdCommand(0x32);
	HAL_Delay(5);
	lcdCommand(0x28);
	HAL_Delay(5);
	lcdCommand(DISPLAY_ON);
	HAL_Delay(5);
	lcdCommand(0x06);
	HAL_Delay(5);
	lcdCommand(CLEAR_DISPLAY);			// 약 2ms 필요
	HAL_Delay(2);
}

void lcdString(char *str) {
	while(*str)lcdData(*str++);
}

void moveCursor(uint8_t row, uint8_t col) {
	lcdCommand(0x80 | row << 6 | col);
}