This is the low level driver for the HX8347A display controller.

It provides basic functions for initializing, writing and reading the controller. In addition to hardware control and use of the LCD controller internal functions.

Warning: This driver is not reentrant and can not be used in interrupt service routines without extra care

Before writing data to the display call hx8347a_init() which will set up the physical interface and the display. A configuration file conf_hx8347a.h is needed to define which interface to use, pin connections and communication speed.

An example conf_hx8347a.h file for the XMEGA could look like:

#define CONF_HX8347A_USART_SPI     &USARTD1
#define CONF_HX8347A_CLOCK_SPEED   500000UL
#define CONF_HX8347A_CS_PIN        IOPORT_CREATE_PIN(PORTD, 4)
#define CONF_HX8347A_TE_PIN        IOPORT_CREATE_PIN(PORTD, 2)
#define CONF_HX8347A_BACKLIGHT_PIN IOPORT_CREATE_PIN(PORTD, 0)
#define CONF_HX8347A_RESET_PIN     IOPORT_CREATE_PIN(PORTD, 1)

Dependencies

This driver depends on the following modules:

General Purpose Input/Output for IO port control.
System Clock Management for clock speed and functions.
USART in SPI (Serial Peripheral Interface) mode or Serial Peripheral Interface (SPI) for communication with the controller.

Modules
	Related Project(s)
	In this section you can find all the projects related to the HX8347A Display Controller Low Level driver.

Macros
#define	HX8347A_COLOR(r, g, b)
	This macro generates a 16-bit native color for the display from a 24-bit RGB value. More...

#define	HX8347A_DEFAULT_HEIGHT 320
	Height of display using default orientation. More...

#define	HX8347A_DEFAULT_WIDTH 240
	Width of display using default orientation. More...

#define	HX8347A_FLIP_X 1
	Bit mask for flipping X for hx8347a_set_orientation() More...

#define	HX8347A_FLIP_Y 2
	Bit mask for flipping Y for hx8347a_set_orientation() More...

#define	HX8347A_SWITCH_XY 4
	Bit mask for swapping X and Y for hx8347a_set_orientation() More...

#define	HX8347A_SWITCH_XY_HEIGHT 240
	Height of display using swapped X/Y orientation. More...

#define	HX8347A_SWITCH_XY_WIDTH 320
	Width of display using swapped X/Y orientation. More...

Typedefs
typedef uint16_t	hx8347a_color_t

typedef int16_t	hx8347a_coord_t

Register manipulation functions
void	hx8347a_write_register (uint8_t address, uint8_t value)
	Write a specific register in the controller with a single byte. More...

uint8_t	hx8347a_read_register (uint8_t address)
	Read the value of a specific register in the controller. More...

void	hx8347a_clear_register (uint8_t address, uint8_t bitmask)
	Helper function for easier register access. More...

void	hx8347a_set_register (uint8_t address, uint8_t bitmask)
	Helper function for easier register access. More...

Controller primitive graphical functions
hx8347a_color_t	hx8347a_read_gram (void)
	Read a single color from the graphical memory. More...

void	hx8347a_write_gram (hx8347a_color_t color)
	Write the graphical memory with a single color pixel. More...

void	hx8347a_set_top_left_limit (hx8347a_coord_t x, hx8347a_coord_t y)
	Set the display top left drawing limit. More...

void	hx8347a_set_bottom_right_limit (hx8347a_coord_t x, hx8347a_coord_t y)
	Set the display bottom right drawing limit. More...

void	hx8347a_set_limits (hx8347a_coord_t start_x, hx8347a_coord_t start_y, hx8347a_coord_t end_x, hx8347a_coord_t end_y)
	Set the fully display drawing limits. More...

void	hx8347a_set_orientation (uint8_t flags)
	Set the display orientation. More...

void	hx8347a_copy_pixels_to_screen (const hx8347a_color_t *pixels, uint32_t count)
	Copy pixels from SRAM to the screen. More...

void	hx8347a_copy_progmem_pixels_to_screen (hx8347a_color_t PROGMEM_PTR_T pixels, uint32_t count)
	Copy pixels from progmem to the screen. More...

void	hx8347a_copy_pixels_from_screen (hx8347a_color_t *pixels, uint32_t count)
	Copy pixels from the screen to a pixel buffer. More...

void	hx8347a_duplicate_pixel (const hx8347a_color_t color, uint32_t count)
	Write a set color to the screen. More...

Controller and display initialization and management
void	hx8347a_init (void)
	Initialize the controller. More...

void	hx8347a_exit_standby (void)
	Send display commands to exit standby mode. More...

void	hx8347a_reset_display (void)
	Reset the display using the digital control interface. More...

static __always_inline void	hx8347a_backlight_on (void)
	Function to turn on the display back light. More...

static __always_inline void	hx8347a_backlight_off (void)
	Function to turn off the display back light. More...

#define HX8347A_COLOR	(	r,
		g,
		b
	)

Value:

Swap16((((uint16_t)b >> 3) << 11) |\
           (((uint16_t)g >> 2) << 5) |\
           (((uint16_t)r >> 3) << 0))

This macro generates a 16-bit native color for the display from a 24-bit RGB value.

Referenced by hx8347a_copy_pixels_from_screen(), hx8347a_read_gram(), and main().

#define HX8347A_DEFAULT_HEIGHT 320

Height of display using default orientation.

Referenced by gfx_hx8347a_init(), gfx_hx8347a_set_orientation(), and main().

#define HX8347A_DEFAULT_WIDTH 240

Width of display using default orientation.

Referenced by gfx_hx8347a_init(), gfx_hx8347a_set_orientation(), and main().

#define HX8347A_FLIP_X 1

Bit mask for flipping X for hx8347a_set_orientation()

Referenced by hx8347a_set_orientation().

#define HX8347A_FLIP_Y 2

Bit mask for flipping Y for hx8347a_set_orientation()

Referenced by hx8347a_set_orientation().

#define HX8347A_SWITCH_XY 4

Bit mask for swapping X and Y for hx8347a_set_orientation()

Referenced by hx8347a_set_orientation().

#define HX8347A_SWITCH_XY_HEIGHT 240

Height of display using swapped X/Y orientation.

Referenced by gfx_hx8347a_set_orientation().

#define HX8347A_SWITCH_XY_WIDTH 320

Width of display using swapped X/Y orientation.

Referenced by gfx_hx8347a_set_orientation().

typedef uint16_t hx8347a_color_t

typedef int16_t hx8347a_coord_t

static __always_inline void hx8347a_backlight_off ( void )

static

Function to turn off the display back light.

Use this function to simply set the pin controlling the back light low to turn off the back light.

References gpio_set_pin_low.

static __always_inline void hx8347a_backlight_on ( void )

static

Function to turn on the display back light.

Use this function to simply set the pin controlling the back light high to turn on the back light.

Note: It is up to the top application if other means of controlling this pin should be used, e.g. a PWM signal to be able to dim the display.

References gpio_set_pin_high.

Referenced by gfx_hx8347a_init(), and main().

void hx8347a_clear_register	(	uint8_t	address,
		uint8_t	bitmask
	)

Helper function for easier register access.

Use this function to clear specific bits in the controller registers.

Parameters

address	the address of the register to clear
bitmask	the bitmask of the specific bits to clear

References hx8347a_read_register(), and hx8347a_write_register().

Referenced by hx8347a_exit_standby().

void hx8347a_copy_pixels_from_screen	(	hx8347a_color_t *	pixels,
		uint32_t	count
	)

Copy pixels from the screen to a pixel buffer.

Use this function to copy pixels from the display to an internal SRAM buffer. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Parameters

pixels	pointer to the pixel buffer to read to
count	number of pixels to read

References Assert, HX8347A_COLOR, hx8347a_deselect_chip(), hx8347a_read_byte(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, and HX8347A_START_READREG.

void hx8347a_copy_pixels_to_screen	(	const hx8347a_color_t *	pixels,
		uint32_t	count
	)

Copy pixels from SRAM to the screen.

Used to copy a large quantitative of data to the screen in one go. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Parameters

pixels	pointer to the pixel data
count	number of pixels to copy to the screen

References Assert, byte_count, hx8347a_deselect_chip(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, HX8347A_START_WRITEREG, and hx8347a_write_packet().

Referenced by main().

void hx8347a_copy_progmem_pixels_to_screen	(	hx8347a_color_t PROGMEM_PTR_T	pixels,
		uint32_t	count
	)

Copy pixels from progmem to the screen.

This function can be used to copy data from program memory (flash) to the display. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Parameters

pixels	pointer to the progmem data
count	number of pixels to write

References Assert, byte_count, hx8347a_deselect_chip(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, HX8347A_START_WRITEREG, PROGMEM_PTR_T, and PROGMEM_READ_BYTE.

void hx8347a_duplicate_pixel	(	const hx8347a_color_t	color,
		uint32_t	count
	)

Write a set color to the screen.

Use this function to write a certain number of pixels to the same color within a set limit. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Parameters

color	the color to write to the display
count	the number of pixels to write with this color

References Assert, hx8347a_deselect_chip(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, HX8347A_START_WRITEREG, and hx8347a_write_packet().

Referenced by main().

void hx8347a_exit_standby ( void )

Send display commands to exit standby mode.

This function is used to exit the display standby mode, which is the default mode after a reset signal to the display.

References delay_ms, hx8347a_clear_register(), HX8347A_OSC_EN, HX8347A_OSCCTRL1, HX8347A_POWERCTRL1, hx8347a_set_register(), and HX8347A_STB.

Referenced by hx8347a_init().

void hx8347a_init ( void )

Initialize the controller.

Used to initialize the HX8347A display controller by setting up the hardware interface, and setting up the controller according to the manufacturer's description. It also set up the screen orientation to the default state (portrait).

References hx8347a_controller_init_registers(), hx8347a_exit_standby(), hx8347a_interface_init(), and hx8347a_reset_display().

Referenced by gfx_hx8347a_init(), and main().

hx8347a_color_t hx8347a_read_gram ( void )

Read a single color from the graphical memory.

Use this function to read a color from the graphical memory of the controller. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Return values

hx8347a_color_t the read color pixel

References HX8347A_COLOR, hx8347a_deselect_chip(), hx8347a_read_byte(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, and HX8347A_START_READREG.

Referenced by gfx_hx8347a_get_pixel().

uint8_t hx8347a_read_register ( uint8_t address )

Read the value of a specific register in the controller.

Use this function to get the value of a specific register in the display controller.

Parameters

address the address of the register to read

References hx8347a_deselect_chip(), hx8347a_read_byte(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), and HX8347A_START_READREG.

Referenced by hx8347a_clear_register(), hx8347a_set_orientation(), and hx8347a_set_register().

void hx8347a_reset_display ( void )

Reset the display using the digital control interface.

Controls the reset pin of the display controller to reset the display.

References delay_ms, gpio_set_pin_high, and gpio_set_pin_low.

Referenced by hx8347a_init().

void hx8347a_set_bottom_right_limit	(	hx8347a_coord_t	x,
		hx8347a_coord_t	y
	)

Set the display bottom right drawing limit.

Use this function to set the bottom right corner of the drawing limit box.

Parameters

x	the x coordinate of the bottom right corner
y	the y coordinate of the bottom right corner

References HX8347A_COLENDHIGH, HX8347A_COLENDLOW, HX8347A_ROWENDHIGH, HX8347A_ROWENDLOW, and hx8347a_write_register().

Referenced by hx8347a_set_limits(), and main().

void hx8347a_set_limits	(	hx8347a_coord_t	start_x,
		hx8347a_coord_t	start_y,
		hx8347a_coord_t	end_x,
		hx8347a_coord_t	end_y
	)

Set the fully display drawing limits.

Use this function to set the full drawing limit box.

Parameters

start_x	the x coordinate of the top left corner
start_y	the y coordinate of the top left corner
end_x	the x coordinate of the bottom right corner
end_y	the y coordinate of the bottom right corner

References hx8347a_set_bottom_right_limit(), and hx8347a_set_top_left_limit().

void hx8347a_set_orientation ( uint8_t flags )

Set the display orientation.

This is used for orienting the display in different directions, the most obvious once are landscape or portrait mode.

Example of usage (for setting landscape mode):

hx8347a_set_orientation(HX8347A_FLIP_Y | HX8347A_SWITCH_XY);

Or use the GFX defines:

hx8347a_set_orientation(GFX_FLIP_Y | GFX_SWITCH_XY);

Parameters

flags different flags used to define what orientation to use.

References HX8347A_FLIP_X, HX8347A_FLIP_X_MASK, HX8347A_FLIP_Y, HX8347A_FLIP_Y_MASK, HX8347A_MEMACCESSCTRL, hx8347a_read_register(), HX8347A_SWITCH_XY, HX8347A_SWITCH_XY_MASK, and hx8347a_write_register().

Referenced by gfx_hx8347a_set_orientation().

void hx8347a_set_register	(	uint8_t	address,
		uint8_t	bitmask
	)

Helper function for easier register access.

Use this function to set specific bits in the controller registers.

Parameters

address	the address of the controller register to set
bitmask	the bitmask describing which bit to set

References hx8347a_read_register(), and hx8347a_write_register().

Referenced by hx8347a_exit_standby().

void hx8347a_set_top_left_limit	(	hx8347a_coord_t	x,
		hx8347a_coord_t	y
	)

Set the display top left drawing limit.

Use this function to set the top left limit of the drawing limit box.

Parameters

x	the x coordinate of the top left corner
y	the y coordinate of the top left corner

References HX8347A_COLSTARTHIGH, HX8347A_COLSTARTLOW, HX8347A_ROWSTARTHIGH, HX8347A_ROWSTARTLOW, and hx8347a_write_register().

Referenced by hx8347a_set_limits(), and main().

void hx8347a_write_gram ( hx8347a_color_t color )

Write the graphical memory with a single color pixel.

Use this function to write a single color pixel to the controller memory. Limits have to be set prior to calling this function, e.g.:

hx8347a_set_top_left_limit(0, 0);
hx8347a_set_bottom_right_limit(320, 240);
...

Parameters

color the color pixel to write to the screen

References Assert, hx8347a_deselect_chip(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), HX8347A_SRAMWRITE, and HX8347A_START_WRITEREG.

Referenced by gfx_hx8347a_draw_line_pixel(), and gfx_hx8347a_draw_pixel().

void hx8347a_write_register	(	uint8_t	address,
		uint8_t	value
	)

Write a specific register in the controller with a single byte.

Use this function to write a value to a specific register in the display controller.

Parameters

address	the address of the register to write
value	the value to be written

References hx8347a_deselect_chip(), hx8347a_select_chip(), hx8347a_select_register(), hx8347a_send_byte(), and HX8347A_START_WRITEREG.

Referenced by hx8347a_clear_register(), hx8347a_controller_init_registers(), hx8347a_set_bottom_right_limit(), hx8347a_set_orientation(), hx8347a_set_register(), and hx8347a_set_top_left_limit().

Microchip® Advanced Software Framework

Dependencies

Modules

Macros

Typedefs

Register manipulation functions

Controller primitive graphical functions

Controller and display initialization and management