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/*
Copyright 2022
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>
/**
* \defgroup hd44780
*
* HD44780 Character LCD Driver
* \{
*/
/*
* HD44780 instructions
* https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
* Table 6 (p24)
*/
// Clear display
#define HD44780_CMD_CLEAR_DISPLAY 0x01
// Return home
#define HD44780_CMD_RETURN_HOME 0x02
// Entry mode set
#define HD44780_CMD_ENTRY_MODE 0x04
#define HD44780_ENTRY_MODE_INC 0x02 // I/D
#define HD44780_ENTRY_MODE_SHIFT 0x01 // S
// Display on/off control
#define HD44780_CMD_DISPLAY 0x08
#define HD44780_DISPLAY_ON 0x04 // D
#define HD44780_DISPLAY_CURSOR 0x02 // C
#define HD44780_DISPLAY_BLINK 0x01 // B
// Cursor or display shift
#define HD44780_CMD_MOVE 0x10
#define HD44780_MOVE_DISPLAY 0x08 // S/C
#define HD44780_MOVE_RIGHT 0x04 // R/L
// Function set
#define HD44780_CMD_FUNCTION 0x20
#define HD44780_FUNCTION_8_BIT 0x10 // DL
#define HD44780_FUNCTION_2_LINES 0x08 // N
#define HD44780_FUNCTION_5X10_DOTS 0x04 // F
// Set CGRAM address
#define HD44780_CMD_SET_CGRAM_ADDRESS 0x40
// Set DDRAM address
#define HD44780_CMD_SET_DDRAM_ADDRESS 0x80
// Bitmask for busy flag when reading
#define HD44780_BUSY_FLAG 0x80
/**
* \brief Write a byte to the display.
*
* \param data The byte to send to the display.
* \param isData Whether the byte is an instruction or character data.
*/
void hd44780_write(uint8_t data, bool isData);
/**
* \brief Read a byte from the display.
*
* \param isData Whether to read the current cursor position, or the character at the cursor.
*
* \return If `isData` is `true`, the returned byte will be the character at the current DDRAM address. Otherwise, it will be the current DDRAM address and the busy flag.
*/
uint8_t hd44780_read(bool isData);
/**
* \brief Indicates whether the display is currently processing, and cannot accept instructions.
*
* \return `true` if the display is busy.
*/
bool hd44780_busy(void);
/**
* \brief Send a command to the display. Refer to the datasheet for the valid commands.
*
* This function waits for the display to clear the busy flag before sending the command.
*
* \param command The command to send.
*/
void hd44780_command(uint8_t command);
/**
* \brief Send a byte of data to the display.
*
* This function waits for the display to clear the busy flag before sending the data.
*
* \param data The byte of data to send.
*/
void hd44780_data(uint8_t data);
/**
* \brief Clear the display.
*
* This function is called on init.
*/
void hd44780_clear(void);
/**
* \brief Move the cursor to the home position.
*
* This function is called on init.
*/
void hd44780_home(void);
/**
* \brief Turn the display on, and/or set the cursor position.
*
* This function is called on init.
*
* \param cursor Whether to show the cursor.
* \param blink Whether to blink the cursor, if shown.
*/
void hd44780_on(bool cursor, bool blink);
/**
* \brief Turn the display off.
*/
void hd44780_off(void);
/**
* \brief Set the CGRAM address.
*
* This function is used when defining custom characters.
*
* \param address The CGRAM address to move to, from `0x00` to `0x3F`.
*/
void hd44780_set_cgram_address(uint8_t address);
/**
* \brief Set the DDRAM address.
*
* This function is used when printing characters to the display, and setting the cursor.
*
* \param address The DDRAM address to move to, from `0x00` to `0x7F`.
*/
void hd44780_set_ddram_address(uint8_t address);
/**
* \brief Initialize the display.
*
* This function should be called only once, before any of the other functions can be called.
*
* \param cursor Whether to show the cursor.
* \param blink Whether to blink the cursor, if shown.
*/
void hd44780_init(bool cursor, bool blink);
/**
* \brief Move the cursor to the specified position on the display.
*
* \param col The column number to move to, from 0 to 15 on 16x2 displays.
* \param line The line number to move to, either 0 or 1 on 16x2 displays.
*/
void hd44780_set_cursor(uint8_t col, uint8_t line);
/**
* \brief Define a custom character.
*
* \param index The index of the custom character to define, from 0 to 7.
* \param data An array of 8 bytes containing the 5-bit row data of the character, where the first byte is the topmost row, and the least significant bit of each byte is the rightmost column.
*/
void hd44780_define_char(uint8_t index, uint8_t *data);
/**
* \brief Print a character to the display. The newline character will move the cursor to the start of the next line.
*
* The exact character shown may depend on the ROM code of your particular display - refer to the datasheet for the full character set.
*
* \param c The character to print.
*/
void hd44780_putc(char c);
/**
* \brief Print a string of characters to the display.
*
* \param s The string to print.
*/
void hd44780_puts(const char *s);
#if defined(__AVR__) || defined(__DOXYGEN__)
/**
* \brief Define a custom character from PROGMEM.
*
* On ARM devices, this function is simply an alias of hd44780_define_char().
*
* \param index The index of the custom character to define, from 0 to 7.
* \param data A PROGMEM array of 8 bytes containing the 5-bit row data of the character, where the first byte is the topmost row, and the least significant bit of each byte is the rightmost column.
*/
void hd44780_define_char_P(uint8_t index, const uint8_t *data);
/**
* \brief Print a string of characters from PROGMEM to the display.
*
* On ARM devices, this function is simply an alias of hd44780_puts().
*
* \param s The PROGMEM string to print.
*/
void hd44780_puts_P(const char *s);
#else
# define hd44780_define_char_P(index, data) hd44780_define_char(index, data)
# define hd44780_puts_P(s) hd44780_puts(s)
#endif
/** \} */
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