Driver for PCD8544 LCD displays. More...

Detailed Description

Driver for PCD8544 LCD displays.

Files
file	pcd8544.h
	Interface definition for the PCD8544 LCD driver.

file	pcd8544_internal.h
	Internal definitions for PCD8544 displays.

Data Structures
struct	pcd8544_t
	PCD8544 device descriptor. More...

Functions
int	pcd8544_init (pcd8544_t *dev, spi_t spi, gpio_t cs, gpio_t reset, gpio_t mode)
	Initialize the given display. More...

void	pcd8544_set_contrast (const pcd8544_t *dev, uint8_t contrast)
	Set the contrast for the given display. More...

void	pcd8544_set_tempcoef (const pcd8544_t *dev, uint8_t coef)
	Set the temperature coefficient for the given display. More...

void	pcd8544_set_bias (const pcd8544_t *dev, uint8_t bias)
	Set the internal BIAS for the given display. More...

void	pcd8544_write_img (const pcd8544_t *dev, const uint8_t img[])
	Write an image to memory of the given display. More...

void	pcd8544_write_c (const pcd8544_t *dev, uint8_t x, uint8_t y, const char c)
	Write a single ASCII character to the display. More...

void	pcd8544_write_s (const pcd8544_t dev, uint8_t x, uint8_t y, const char str)
	Write a string to a given position on the display. More...

void	pcd8544_clear (const pcd8544_t *dev)
	Clear the current display (clear the display memory) More...

void	pcd8544_invert (pcd8544_t *dev)
	Invert the display (toggles dark and bright pixels) More...

int	pcd8544_is_inverted (const pcd8544_t *dev)
	Get the current inversion status of the display. More...

void	pcd8544_poweron (const pcd8544_t *dev)
	Power on the display. More...

void	pcd8544_poweroff (const pcd8544_t *dev)
	Poser off the display. More...

void	pcd8544_riot (const pcd8544_t *dev)
	I wonder what this does -> find out! More...

Definition of display dimensions
#define	PCD8544_RES_X (84U)
	pixels per row

#define	PCD8544_RES_Y (48U)
	pixels per column

#define	PCD8544_COLS (14U)
	characters per row

#define	PCD8544_ROWS (6U)
	characters per column

Default values for temperature compensation and contrast
#define	PCD8544_DEFAULT_CONTRAST (45U)

#define	PCD8544_DEFAULT_BIAS (3U)

#define	PCD8544_DEFAULT_TEMPCOEF (0U)

Function Documentation

◆ pcd8544_clear()

void pcd8544_clear ( const pcd8544_t * dev )

Clear the current display (clear the display memory)

Parameters

[in] dev device descriptor of display to use

◆ pcd8544_init()

int pcd8544_init	(	pcd8544_t *	dev,
		spi_t	spi,
		gpio_t	cs,
		gpio_t	reset,
		gpio_t	mode
	)

Initialize the given display.

Parameters

[in]	dev	device descriptor of display to use
[in]	spi	SPI bus the display is connected to
[in]	cs	GPIO pin that is connected to the CS pin
[in]	reset	GPIO pin that is connected to the RESET pin
[in]	mode	GPIO pin that is connected to the MODE pin

Returns: 0 on success; <0 on error

◆ pcd8544_invert()

void pcd8544_invert ( pcd8544_t * dev )

Invert the display (toggles dark and bright pixels)

Parameters

[in] dev device descriptor of display to use

◆ pcd8544_is_inverted()

int pcd8544_is_inverted ( const pcd8544_t * dev )

Get the current inversion status of the display.

Parameters

[in] dev device descriptor of display to use

Returns: 0 -> display is not inverted; 1 -> display is inverted

◆ pcd8544_poweroff()

void pcd8544_poweroff ( const pcd8544_t * dev )

Poser off the display.

Parameters

[in] dev device descriptor of display to use

◆ pcd8544_poweron()

void pcd8544_poweron ( const pcd8544_t * dev )

Power on the display.

Parameters

[in] dev device descriptor of display to use

◆ pcd8544_riot()

void pcd8544_riot ( const pcd8544_t * dev )

I wonder what this does -> find out!

Parameters

[in] dev device descriptor of display to use

◆ pcd8544_set_bias()

void pcd8544_set_bias	(	const pcd8544_t *	dev,
		uint8_t	bias
	)

Set the internal BIAS for the given display.

Note: Look at the datasheet for more information

Parameters

[in]	dev	device descriptor of display to use
[in]	bias	the BIAS to use [0 - 7]

◆ pcd8544_set_contrast()

void pcd8544_set_contrast	(	const pcd8544_t *	dev,
		uint8_t	contrast
	)

Set the contrast for the given display.

Note: A contrast value of 45 yields good results for 3V3

Parameters

[in]	dev	display device descriptor
[in]	contrast	targeted contrast value [0 - 127]

◆ pcd8544_set_tempcoef()

void pcd8544_set_tempcoef	(	const pcd8544_t *	dev,
		uint8_t	coef
	)

Set the temperature coefficient for the given display.

Note: Look at the datasheet for more information

Parameters

[in]	dev	device descriptor of display to use
[in]	coef	temperature coefficient to use [0 - 3]

◆ pcd8544_write_c()

void pcd8544_write_c	(	const pcd8544_t *	dev,
		uint8_t	x,
		uint8_t	y,
		const char	c
	)

Write a single ASCII character to the display.

The position of the character is specified in columns (x) and rows (y)

Parameters

[in]	dev	device descriptor of display to use
[in]	x	column to put the character [0 - 13]
[in]	y	row to put the character [0 - 5]
[in]	c	ASCII code for the character to write

◆ pcd8544_write_img()

void pcd8544_write_img	(	const pcd8544_t *	dev,
		const uint8_t	img[]
	)

Write an image to memory of the given display.

The image must be given as a char array with 504 elements. Each bit in the array represents one pixel on the display. Each byte in the array contains 8 stacked pixels, from top to bottom. So byte[0] contains the pixels from (0,0) to (0,7), byte[1] (1,0) to (1,7) and byte[503] the pixels from (83,40) to (83,47) -> see the 'horizontal addressing' section in the datasheet.

Parameters

[in]	dev	device descriptor of display to use
[in]	img	uint8_t array with image data (must be of size := 504)

◆ pcd8544_write_s()

void pcd8544_write_s	(	const pcd8544_t *	dev,
		uint8_t	x,
		uint8_t	y,
		const char *	str
	)

Write a string to a given position on the display.

This function prints a given string to the given position on the display. The position is given in terms of columns (x) and rows (y). If a string does not fit completely in the given position (it overflows its row), the overflowing part of the string is cut off.

Parameters

[in]	dev	device descriptor of display to use
[in]	x	starting column of the string [0 - 13]
[in]	y	row to write the string to [0 - 5]
[in]	str	string to write to the display

Detailed Description

Files

Data Structures

Functions

Definition of display dimensions

Default values for temperature compensation and contrast

Function Documentation

◆ pcd8544_clear()

◆ pcd8544_init()

◆ pcd8544_invert()

◆ pcd8544_is_inverted()

◆ pcd8544_poweroff()

◆ pcd8544_poweron()

◆ pcd8544_riot()

◆ pcd8544_set_bias()

◆ pcd8544_set_contrast()

◆ pcd8544_set_tempcoef()

◆ pcd8544_write_c()

◆ pcd8544_write_img()

◆ pcd8544_write_s()