Interface definitions for the ESP32-compatible I2C LCD1602 component. More...

#include <stdbool.h>
#include "smbus.h"

Data Structures
struct	i2c_lcd1602_info_t
	Structure containing information related to the I2C-LCD1602 device. More...

Macros
#define	I2C_LCD1602_CHARACTER_CUSTOM_0 0b00001000
	User-defined custom symbol in index 0.

#define	I2C_LCD1602_CHARACTER_CUSTOM_1 0b00001001
	User-defined custom symbol in index 1.

#define	I2C_LCD1602_CHARACTER_CUSTOM_2 0b00001010
	User-defined custom symbol in index 2.

#define	I2C_LCD1602_CHARACTER_CUSTOM_3 0b00001011
	User-defined custom symbol in index 3.

#define	I2C_LCD1602_CHARACTER_CUSTOM_4 0b00001100
	User-defined custom symbol in index 4.

#define	I2C_LCD1602_CHARACTER_CUSTOM_5 0b00001101
	User-defined custom symbol in index 5.

#define	I2C_LCD1602_CHARACTER_CUSTOM_6 0b00001110
	User-defined custom symbol in index 6.

#define	I2C_LCD1602_CHARACTER_CUSTOM_7 0b00001111
	User-defined custom symbol in index 7.

#define	I2C_LCD1602_CHARACTER_ALPHA 0b11100000
	Lower-case alpha symbol.

#define	I2C_LCD1602_CHARACTER_BETA 0b11100010
	Lower-case beta symbol.

#define	I2C_LCD1602_CHARACTER_THETA 0b11110010
	Lower-case theta symbol.

#define	I2C_LCD1602_CHARACTER_PI 0b11110111
	Lower-case pi symbol.

#define	I2C_LCD1602_CHARACTER_OMEGA 0b11110100
	Upper-case omega symbol.

#define	I2C_LCD1602_CHARACTER_SIGMA 0b11110110
	Upper-case sigma symbol.

#define	I2C_LCD1602_CHARACTER_INFINITY 0b11110011
	Infinity symbol.

#define	I2C_LCD1602_CHARACTER_DEGREE 0b11011111
	Degree symbol.

#define	I2C_LCD1602_CHARACTER_ARROW_RIGHT 0b01111110
	Arrow pointing right symbol.

#define	I2C_LCD1602_CHARACTER_ARROW_LEFT 0b01111111
	Arrow pointing left symbol.

#define	I2C_LCD1602_CHARACTER_SQUARE 0b11011011
	Square outline symbol.

#define	I2C_LCD1602_CHARACTER_DOT 0b10100101
	Centred dot symbol.

#define	I2C_LCD1602_CHARACTER_DIVIDE 0b11111101
	Division sign symbol.

#define	I2C_LCD1602_CHARACTER_BLOCK 0b11111111
	5x8 filled block

#define	I2C_LCD1602_ERROR_CHECK(x)

Enumerations
enum	i2c_lcd1602_custom_index_t { I2C_LCD1602_INDEX_CUSTOM_0 = 0, I2C_LCD1602_INDEX_CUSTOM_1, I2C_LCD1602_INDEX_CUSTOM_2, I2C_LCD1602_INDEX_CUSTOM_3, I2C_LCD1602_INDEX_CUSTOM_4, I2C_LCD1602_INDEX_CUSTOM_5, I2C_LCD1602_INDEX_CUSTOM_6, I2C_LCD1602_INDEX_CUSTOM_7 }
	Enum of valid indexes for definitions of user-defined characters. More...

Functions
i2c_lcd1602_info_t *	i2c_lcd1602_malloc (void)
	Construct a new I2C-LCD1602 info instance. New instance should be initialised before calling other functions. More...

void	i2c_lcd1602_free (i2c_lcd1602_info_t **tsl2561_info)
	Delete an existing I2C-LCD1602 info instance. More...

esp_err_t	i2c_lcd1602_init (i2c_lcd1602_info_t i2c_lcd1602_info, smbus_info_t smbus_info, bool backlight, uint8_t num_rows, uint8_t num_columns, uint8_t num_visible_columns)
	Initialise a I2C-LCD1602 info instance with the specified SMBus information. More...

esp_err_t	i2c_lcd1602_reset (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Reset the display. Custom characters will be cleared. More...

esp_err_t	i2c_lcd1602_clear (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Clears entire display (clears DDRAM) and returns cursor to home position. DDRAM content is cleared, CGRAM content is not changed. More...

esp_err_t	i2c_lcd1602_home (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Move cursor to home position. Also resets any display shift that may have occurred. DDRAM content is not changed. CGRAM content is not changed. More...

esp_err_t	i2c_lcd1602_move_cursor (const i2c_lcd1602_info_t *i2c_lcd1602_info, uint8_t col, uint8_t row)
	Move cursor to specified column and row position. This is where a new character will appear. More...

esp_err_t	i2c_lcd1602_set_backlight (i2c_lcd1602_info_t *i2c_lcd1602_info, bool enable)
	Enable or disable the LED backlight. More...

esp_err_t	i2c_lcd1602_set_display (i2c_lcd1602_info_t *i2c_lcd1602_info, bool enable)
	Enable or disable the display. When disabled, the backlight is not affected, but any contents of the DDRAM is not displayed, nor is the cursor. The display is "blank". Re-enabling the display does not affect the contents of DDRAM or the state or position of the cursor. More...

esp_err_t	i2c_lcd1602_set_cursor (i2c_lcd1602_info_t *i2c_lcd1602_info, bool enable)
	Enable or disable display of the underline cursor. If enabled, this visually indicates where the next character written to the display will appear. It may be enabled alongside the blinking cursor, however the visual result is inelegant. More...

esp_err_t	i2c_lcd1602_set_blink (i2c_lcd1602_info_t *i2c_lcd1602_info, bool enable)
	Enable or disable display of the blinking block cursor. If enabled, this visually indicates where the next character written to the display will appear. It may be enabled alongside the underline cursor, however the visual result is inelegant. More...

esp_err_t	i2c_lcd1602_set_left_to_right (i2c_lcd1602_info_t *i2c_lcd1602_info)
	Set cursor movement direction following each character write to produce left-to-right text. More...

esp_err_t	i2c_lcd1602_set_right_to_left (i2c_lcd1602_info_t *i2c_lcd1602_info)
	Set cursor movement direction following each character write to produce right-to-left text. More...

esp_err_t	i2c_lcd1602_set_auto_scroll (i2c_lcd1602_info_t *i2c_lcd1602_info, bool enable)
	Enable or disable auto-scroll of display. When enabled, the display will scroll as characters are written to maintain the cursor position on-screen. Left-to-right text will appear to be right-justified from the cursor position. When disabled, the display will not scroll and the cursor will move on-screen. Left-to-right text will appear to be left-justified from the cursor position. More...

esp_err_t	i2c_lcd1602_scroll_display_left (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Scroll the display one position to the left. On-screen text will appear to move to the right. More...

esp_err_t	i2c_lcd1602_scroll_display_right (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Scroll the display one position to the right. On-screen text will appear to move to the left. More...

esp_err_t	i2c_lcd1602_move_cursor_left (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Move the cursor one position to the left, even if it is invisible. This affects where the next character written to the display will appear. More...

esp_err_t	i2c_lcd1602_move_cursor_right (const i2c_lcd1602_info_t *i2c_lcd1602_info)
	Move the cursor one position to the right, even if it is invisible. This affects where the next character written to the display will appear. More...

esp_err_t	i2c_lcd1602_define_char (const i2c_lcd1602_info_t *i2c_lcd1602_info, i2c_lcd1602_custom_index_t index, const uint8_t pixelmap[])
	Define a custom character from an array of pixel data. More...

esp_err_t	i2c_lcd1602_write_char (const i2c_lcd1602_info_t *i2c_lcd1602_info, uint8_t chr)
	Write a single character to the display at the current position of the cursor. Depending on the active mode, the cursor may move left or right, or the display may shift left or right. Custom characters can be written using the I2C_LCD1602_CHARACTER_CUSTOM_X definitions. More...

esp_err_t	i2c_lcd1602_write_string (const i2c_lcd1602_info_t i2c_lcd1602_info, const char string)
	Write a string of characters to the display, starting at the current position of the cursor. Depending on the active mode, the cursor may move left or right, or the display may shift left or right, after each character is written. More...

Detailed Description

Interface definitions for the ESP32-compatible I2C LCD1602 component.

This component provides structures and functions that are useful for communicating with the device.

Technically, the LCD1602 device is an I2C not SMBus device, however some SMBus protocols can be used to communicate with the device, so it makes sense to use an SMBus interface to manage communication.

Macro Definition Documentation

#define I2C_LCD1602_ERROR_CHECK ( x )

Value:

do {                                     \
        esp_err_t rc = (x);                                                 \
        if (rc != ESP_OK) {                                                 \
            ESP_LOGW(TAG, "I2C error %d at %s:%d", rc, __FILE__, __LINE__); \
        }                                                                   \
    } while(0);

Enumeration Type Documentation

enum i2c_lcd1602_custom_index_t

Enum of valid indexes for definitions of user-defined characters.

Enumerator
I2C_LCD1602_INDEX_CUSTOM_0	Index of first user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_1	Index of second user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_2	Index of third user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_3	Index of fourth user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_4	Index of fifth user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_5	Index of sixth user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_6	Index of seventh user-defined custom symbol.
I2C_LCD1602_INDEX_CUSTOM_7	Index of eighth user-defined custom symbol.

Function Documentation

i2c_lcd1602_info_t* i2c_lcd1602_malloc ( void )

Construct a new I2C-LCD1602 info instance. New instance should be initialised before calling other functions.

Returns: Pointer to new device info instance, or NULL if it cannot be created.

void i2c_lcd1602_free ( i2c_lcd1602_info_t ** tsl2561_info )

Delete an existing I2C-LCD1602 info instance.

Parameters

[in,out] tsl2561_info Pointer to I2C-LCD1602 info instance that will be freed and set to NULL.

esp_err_t i2c_lcd1602_init	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		smbus_info_t *	smbus_info,
		bool	backlight,
		uint8_t	num_rows,
		uint8_t	num_columns,
		uint8_t	num_visible_columns
	)

Initialise a I2C-LCD1602 info instance with the specified SMBus information.

Parameters

[in]	i2c_lcd1602_info	Pointer to I2C-LCD1602 info instance.
[in]	smbus_info	Pointer to SMBus info instance.
[in]	backlight	Initial backlight state.
[in]	num_rows	Maximum number of supported rows for this device. Typical values include 2 (1602) or 4 (2004).
[in]	num_columns	Maximum number of supported columns for this device. Typical values include 40 (1602, 2004).
[in]	num_visible_columns	Number of columns visible at any one time. Typical values include 16 (1602) or 20 (2004).

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_reset ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Reset the display. Custom characters will be cleared.

Parameters

[in] i2c_lcd1602_info Pointer to I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_clear ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Clears entire display (clears DDRAM) and returns cursor to home position. DDRAM content is cleared, CGRAM content is not changed.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_home ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Move cursor to home position. Also resets any display shift that may have occurred. DDRAM content is not changed. CGRAM content is not changed.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_move_cursor	(	const i2c_lcd1602_info_t *	i2c_lcd1602_info,
		uint8_t	col,
		uint8_t	row
	)

Move cursor to specified column and row position. This is where a new character will appear.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	col	Zero-based horizontal index of intended cursor position. Column 0 is the left column.
[in]	row	Zero-based vertical index of intended cursor position. Row 0 is the top row.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_backlight	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		bool	enable
	)

Enable or disable the LED backlight.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	enable	True to enable, false to disable.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_display	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		bool	enable
	)

Enable or disable the display. When disabled, the backlight is not affected, but any contents of the DDRAM is not displayed, nor is the cursor. The display is "blank". Re-enabling the display does not affect the contents of DDRAM or the state or position of the cursor.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	enable	True to enable, false to disable.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_cursor	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		bool	enable
	)

Enable or disable display of the underline cursor. If enabled, this visually indicates where the next character written to the display will appear. It may be enabled alongside the blinking cursor, however the visual result is inelegant.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	enable	True to enable, false to disable.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_blink	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		bool	enable
	)

Enable or disable display of the blinking block cursor. If enabled, this visually indicates where the next character written to the display will appear. It may be enabled alongside the underline cursor, however the visual result is inelegant.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	enable	True to enable, false to disable.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_left_to_right ( i2c_lcd1602_info_t * i2c_lcd1602_info )

Set cursor movement direction following each character write to produce left-to-right text.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_right_to_left ( i2c_lcd1602_info_t * i2c_lcd1602_info )

Set cursor movement direction following each character write to produce right-to-left text.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_set_auto_scroll	(	i2c_lcd1602_info_t *	i2c_lcd1602_info,
		bool	enable
	)

Enable or disable auto-scroll of display. When enabled, the display will scroll as characters are written to maintain the cursor position on-screen. Left-to-right text will appear to be right-justified from the cursor position. When disabled, the display will not scroll and the cursor will move on-screen. Left-to-right text will appear to be left-justified from the cursor position.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	enable	True to enable, false to disable.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_scroll_display_left ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Scroll the display one position to the left. On-screen text will appear to move to the right.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_scroll_display_right ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Scroll the display one position to the right. On-screen text will appear to move to the left.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_move_cursor_left ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Move the cursor one position to the left, even if it is invisible. This affects where the next character written to the display will appear.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_move_cursor_right ( const i2c_lcd1602_info_t * i2c_lcd1602_info )

Move the cursor one position to the right, even if it is invisible. This affects where the next character written to the display will appear.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_define_char	(	const i2c_lcd1602_info_t *	i2c_lcd1602_info,
		i2c_lcd1602_custom_index_t	index,
		const uint8_t	pixelmap[]
	)

Define a custom character from an array of pixel data.

There are eight possible custom characters, and the zero-based index is used to select a character to define. Any existing character definition at that index will be lost. Characters are 5 pixels wide and 8 pixels tall. The pixelmap array consists of up to eight bytes, each byte representing the pixel states per row. The first byte represents the top row. The eighth byte is often left as zero (to leave space for the underline cursor). For each row, the lowest five bits represent pixels that are to be illuminated. The least significant bit represents the right-most pixel. Empty rows will be zero.

NOTE: After calling this function, the DDRAM will not be selected and the cursor position will be undefined. Therefore it is important that the DDRAM address is set following this function, if text is to be written to the display. This can be performed with a call to i2c_lcd1602_home() or i2c_lcd1602_move_cursor().

Custom characters are written using the I2C_LCD1602_CHARACTER_CUSTOM_X definitions.

Parameters

[in]	i2c_lcd1602_info	Pointer to initialised I2C-LCD1602 info instance.
[in]	index	Zero-based index of the character to define. Only values 0-7 are valid.
[in]	pixelmap	An 8-byte array defining the pixel map for the new character definition.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_write_char	(	const i2c_lcd1602_info_t *	i2c_lcd1602_info,
		uint8_t	chr
	)

Write a single character to the display at the current position of the cursor. Depending on the active mode, the cursor may move left or right, or the display may shift left or right. Custom characters can be written using the I2C_LCD1602_CHARACTER_CUSTOM_X definitions.

The display is I2C_LCD1602_NUM_COLUMNS wide, and upon encountering the end of the first line, the cursor will automatically move to the beginning of the second line.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

esp_err_t i2c_lcd1602_write_string	(	const i2c_lcd1602_info_t *	i2c_lcd1602_info,
		const char *	string
	)

Write a string of characters to the display, starting at the current position of the cursor. Depending on the active mode, the cursor may move left or right, or the display may shift left or right, after each character is written.

The display is I2C_LCD1602_NUM_COLUMNS wide, and upon encountering the end of the first line, the cursor will automatically move to the beginning of the second line.

Parameters

[in] i2c_lcd1602_info Pointer to initialised I2C-LCD1602 info instance.

Returns: ESP_OK if successful, otherwise an error constant.

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation