API for the LCM1602 I2C controller for HD44780-based displays. More...

Detailed Description

ID: lcm1602
Name: LCM1602 Display
Category: display
Manufacturer: adafruit sparkfun seeed
Link: https://www.adafruit.com/datasheets/TC1602A-01T.pdf
Connection: i2c gpio

This supports all sizes of HD44780 displays, from 16x2 to 4x20. The controller has no idea of the actual display hardware, so it lets you write farther than you can see. These displays with such controllers are available from various manufacturers with different I2C addresses. Adafruit* TC1602A-01T seems to be a well-documented example. The driver also supports parallel GPIO connections directly to the HD44780 in case you are not using an I2C expander/backpack.

Example for LCM1602 displays that use the I2C bus

    upm::Lcm1602* lcd = new upm::Lcm1602(0, 0x27);
    lcd->setCursor(0,0);
    lcd->write("Hello World");

Code sample for GPIO based LCM1602 displays

    // LCD connection:
    // LCD RS pin to digital pin 8
    // LCD Enable pin to digital pin 13
    // LCD D4 pin to digital pin 2
    // LCD D5 pin to digital pin 3
    // LCD D6 pin to digital pin 4
    // LCD D7 pin to digital pin 5
    // LCD R/W pin to ground
    // 10K trimmer potentiometer:
    //   ends to +5V and ground
    //   wiper to LCD VO pin (pin 3)
    upm::Lcm1602 *lcd = new upm::Lcm1602(8, 13, 2, 3, 4, 5, 20, 2);
    lcd->setCursor(0,0);
    lcd->write("Hello World");
    lcd->setCursor(1,2);
    lcd->write("Hello World");
    printf("Sleeping for 5 seconds\n");
    sleep(5);
    delete lcd;

Public Member Functions
	Lcm1602 (int bus=0, int address=0x27, bool isExpander=true, uint8_t numColumns=16, uint8_t numRows=2)

	Lcm1602 (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t numColumns=16, uint8_t numRows=2)

	~Lcm1602 ()

mraa::Result	write (std::string msg)

mraa::Result	setCursor (int row, int column)

mraa::Result	clear ()

mraa::Result	home ()

mraa::Result	createChar (uint8_t charSlot, uint8_t charData[])

mraa::Result	displayOn ()

mraa::Result	displayOff ()

mraa::Result	cursorOn ()

mraa::Result	cursorOff ()

mraa::Result	cursorBlinkOn ()

mraa::Result	cursorBlinkOff ()

mraa::Result	backlightOn ()

mraa::Result	backlightOff ()

mraa::Result	scrollDisplayLeft ()

mraa::Result	scrollDisplayRight ()

mraa::Result	entryLeftToRight ()

mraa::Result	entryRightToLeft ()

mraa::Result	autoscrollOn ()

mraa::Result	autoscrollOff ()

	Lcm1602 (int bus=0, int address=0x27, bool isExpander=true, uint8_t numColumns=16, uint8_t numRows=2)

	Lcm1602 (uint8_t rs, uint8_t enable, uint8_t d0, uint8_t d1, uint8_t d2, uint8_t d3, uint8_t numColumns=16, uint8_t numRows=2)

	~Lcm1602 ()

upm_result_t	write (std::string msg)

upm_result_t	setCursor (int row, int column)

upm_result_t	clear ()

upm_result_t	home ()

upm_result_t	createChar (uint8_t charSlot, lcm1602_custom_char_t charData)

upm_result_t	displayOn ()

upm_result_t	displayOff ()

upm_result_t	cursorOn ()

upm_result_t	cursorOff ()

upm_result_t	cursorBlinkOn ()

upm_result_t	cursorBlinkOff ()

upm_result_t	backlightOn ()

upm_result_t	backlightOff ()

upm_result_t	scrollDisplayLeft ()

upm_result_t	scrollDisplayRight ()

upm_result_t	entryLeftToRight ()

upm_result_t	entryRightToLeft ()

upm_result_t	autoscrollOn ()

upm_result_t	autoscrollOff ()

Public Member Functions inherited from LCD
mraa::Result	write (int x, int y, std::string msg)

std::string	name ()

Protected Member Functions
mraa::Result	send (uint8_t value, int mode)

mraa::Result	write4bits (uint8_t value)

mraa::Result	expandWrite (uint8_t value)

mraa::Result	pulseEnable (uint8_t value)

virtual mraa::Result	command (uint8_t cmd)

virtual mraa::Result	data (uint8_t data)

upm_result_t	command (uint8_t cmd)

upm_result_t	data (uint8_t data)

Protected Attributes
uint8_t	m_displayControl

uint8_t	m_entryDisplayMode

uint8_t	m_numColumns

uint8_t	m_numRows

uint8_t	m_backlight

int	m_lcd_control_address

mraa::I2c *	m_i2c_lcd_control

lcm1602_context	m_lcm1602

Protected Attributes inherited from LCD
std::string	m_name

Constructor & Destructor Documentation

Lcm1602	(	int	bus = `0`,
		int	address = `0x27`,
		bool	isExpander = `true`,
		uint8_t	numColumns = `16`,
		uint8_t	numRows = `2`
	)

Lcm1602 constructor; calls libmraa initialisation functions

Parameters

bus	I2C bus to use. Default 0 (autodetect).
address	Slave address the LCD is registered on. Default 0x27
isExpander	True if we are dealing with an I2C expander, false otherwise. Default is true.
numColumns	Number of columns the display has. Default 16.
numRows	Number of rows the display has. Default 2.

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Lcm1602	(	uint8_t	rs,
		uint8_t	enable,
		uint8_t	d0,
		uint8_t	d1,
		uint8_t	d2,
		uint8_t	d3,
		uint8_t	numColumns = `16`,
		uint8_t	numRows = `2`
	)

Lcm1602 alternate constructor, used for GPIO based HD44780 controllers supporting RS, Enable, and 4 data pins in 4-bit mode.

Parameters

rs	Register select pin
enable	Enable pin
d0	Data 0 pin
d1	Data 1 pin
d2	Data 2 pin
d3	Data 3 pin
numColumns	Number of columns the display has. Default 16.
numRows	Number of rows the display has. Default 2.

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~Lcm1602 ( )

Lcm1602 destructor

Lcm1602	(	int	bus = `0`,
		int	address = `0x27`,
		bool	isExpander = `true`,
		uint8_t	numColumns = `16`,
		uint8_t	numRows = `2`
	)

Lcm1602 constructor; calls libmraa initialisation functions

Parameters

bus	I2C bus to use. Default 0 (autodetect).
address	Slave address the LCD is registered on. Default 0x27
isExpander	True if we are dealing with an I2C expander, false otherwise. Default is true.
numColumns	Number of columns the display has. Default 16.
numRows	Number of rows the display has. Default 2.

Lcm1602	(	uint8_t	rs,
		uint8_t	enable,
		uint8_t	d0,
		uint8_t	d1,
		uint8_t	d2,
		uint8_t	d3,
		uint8_t	numColumns = `16`,
		uint8_t	numRows = `2`
	)

Lcm1602 alternate constructor, used for GPIO based HD44780 controllers supporting RS, Enable, and 4 data pins in 4-bit mode.

Parameters

rs	Register select pin
enable	Enable pin
d0	Data 0 pin
d1	Data 1 pin
d2	Data 2 pin
d3	Data 3 pin
numColumns	Number of columns the display has. Default 16.
numRows	Number of rows the display has. Default 2.

~Lcm1602 ( )

Lcm1602 destructor

Member Function Documentation

upm_result_t write ( std::string msg )

virtual

Writes a string to the LCD

Parameters

msg	std::string to write to the display; note: only ASCII characters are supported

Returns: Result of the operation

Implements LCD.

upm_result_t setCursor	(	int	row,
		int	column
	)

virtual

Sets the cursor to specified coordinates

Parameters

row	Row to set the cursor to
column	Column to set the cursor to

Returns: Result of the operation

Implements LCD.

upm_result_t clear ( )

virtual

Clears the display of all characters

Returns: Result of the operation

Implements LCD.

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upm_result_t home ( )

virtual

Returns to the original coordinates (0,0)

Returns: Result of the operation

Implements LCD.

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mraa::Result createChar	(	uint8_t	charSlot,
		uint8_t	charData[]
	)

Create a custom character

Parameters

charSlot	the character slot to write, only 8 are available
charData	The character data (8 bytes) making up the character

Returns: Result of operation

upm_result_t displayOn ( )

Turn the display on

Returns: Result of operation

upm_result_t displayOff ( )

Turn the display off

Returns: Result of operation

upm_result_t cursorOn ( )

Turn the cursor on

Returns: Result of operation

upm_result_t cursorOff ( )

Turn the cursor off

Returns: Result of operation

upm_result_t cursorBlinkOn ( )

Turn cursor blink on

Returns: Result of operation

upm_result_t cursorBlinkOff ( )

Turn cursor blink off

Returns: Result of operation

upm_result_t backlightOn ( )

Turn backlight on

Returns: Result of operation

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upm_result_t backlightOff ( )

Turn backlight off

Returns: Result of operation

upm_result_t scrollDisplayLeft ( )

Scroll the display left, without changing the character RAM

Returns: Result of operation

upm_result_t scrollDisplayRight ( )

Scroll the display right, without changing the character RAM

Returns: Result of operation

upm_result_t entryLeftToRight ( )

set the entry mode so that characters are added left to right

Returns: Result of operation

upm_result_t entryRightToLeft ( )

set the entry mode so that characters are added right to left

Returns: Result of operation

upm_result_t autoscrollOn ( )

Right justify text entered from the cursor

Returns: Result of operation

upm_result_t autoscrollOff ( )

Left justify text entered from the cursor

Returns: Result of operation

upm_result_t write ( std::string msg )

virtual

Writes a string to the LCD

Parameters

msg	std::string to write to the display; note: only ASCII characters are supported

Returns: Result of the operation

Implements LCD.

upm_result_t setCursor	(	int	row,
		int	column
	)

virtual

Sets the cursor to specified coordinates

Parameters

row	Row to set the cursor to
column	Column to set the cursor to

Returns: Result of the operation

Implements LCD.

upm_result_t clear ( )

virtual

Clears the display of all characters

Returns: Result of the operation

Implements LCD.

upm_result_t home ( )

virtual

Returns to the original coordinates (0,0)

Returns: Result of the operation

Implements LCD.

upm_result_t createChar	(	uint8_t	charSlot,
		lcm1602_custom_char_t	charData
	)

Create a custom character

Parameters

charSlot	the character slot to write, only 8 are available
charData	The character data (8 bytes) making up the character

Returns: Result of operation

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upm_result_t displayOn ( )

Turn the display on

Returns: Result of operation

upm_result_t displayOff ( )

Turn the display off

Returns: Result of operation

upm_result_t cursorOn ( )

Turn the cursor on

Returns: Result of operation

upm_result_t cursorOff ( )

Turn the cursor off

Returns: Result of operation

upm_result_t cursorBlinkOn ( )

Turn cursor blink on

Returns: Result of operation

upm_result_t cursorBlinkOff ( )

Turn cursor blink off

Returns: Result of operation

upm_result_t backlightOn ( )

Turn backlight on

Returns: Result of operation

upm_result_t backlightOff ( )

Turn backlight off

Returns: Result of operation

upm_result_t scrollDisplayLeft ( )

Scroll the display left, without changing the character RAM

Returns: Result of operation

upm_result_t scrollDisplayRight ( )

Scroll the display right, without changing the character RAM

Returns: Result of operation

upm_result_t entryLeftToRight ( )

set the entry mode so that characters are added left to right

Returns: Result of operation

upm_result_t entryRightToLeft ( )

set the entry mode so that characters are added right to left

Returns: Result of operation

upm_result_t autoscrollOn ( )

Right justify text entered from the cursor

Returns: Result of operation

upm_result_t autoscrollOff ( )

Left justify text entered from the cursor

Returns: Result of operation

Inheritance diagram for Lcm1602:

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Collaboration diagram for Lcm1602:

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The documentation for this class was generated from the following files:

/iotdk/jenkins/workspace/upm-doc-stable/src/lcd/lcm1602.hpp
/iotdk/jenkins/workspace/upm-doc-stable/src/lcd/lcm1602.cxx

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

Member Function Documentation