Longan Nano Display Driver. More...

#include <ST7735S_W160_H80_C16.hpp>

Inheritance diagram for Longan_nano::Display:

Collaboration diagram for Longan_nano::Display:

Classes
struct	_Sprite
	Sprite informations. More...

Public Member Functions
	Display (void)
	constructor Display \| void \| More...

	~Display (void)
	destructor ~Display \| void \| More...

bool	init (void)
	Public init init \| void \|. More...

int	register_sprite (int origin_h, int origin_w, int size_h, int size_w, uint16_t *sprite_ptr)
	public method register_sprite \| int \| int \| int \| int \| uint16_t * \| More...

int	register_sprite (int origin_h, int origin_w, int size_h, int size_w, uint16_t sprite_color)
	public method register_sprite \| int \| int \| int \| int \| uint16_t \| More...

bool	update_sprite (void)
	public method update_sprite \| void \| More...

int	draw_sprite (int origin_h, int origin_w, int size_h, int size_w, uint16_t *sprite_ptr)
	public method draw_sprite \| int \| int \| int \| int \| uint16_t * \| More...

int	draw_sprite (int origin_h, int origin_w, int size_h, int size_w, uint16_t sprite_color)
	public method draw_sprite \| int \| int \| int \| int \| uint16_t \| More...

int	clear (void)
	public method clear \| void \| More...

int	clear (uint16_t color)
	public method clear \| void \| More...

Static Public Member Functions
static uint16_t	color (uint8_t r, uint8_t g, uint8_t b)
	Public Method color \| uint8_t \| uint8_t \| uint8_t \|. More...

Protected Types
enum	_Config { WIDTH = 160, HEIGHT = 80, PIXEL_COUNT = WIDTH *HEIGHT, COLOR_DEPTH = 16, ROW_ADDRESS_OFFSET = 1, COL_ADDRESS_OFFSET = 26, RS_GPIO = GPIOB, RS_PIN = GPIO_PIN_0, RST_GPIO = GPIOB, RST_PIN = GPIO_PIN_1, RESET_DELAY = 1, SPI_CH = SPI0, SPI_CS_GPIO = GPIOB, SPI_CS_PIN = GPIO_PIN_2, SPI_CLK_GPIO = GPIOA, SPI_CLK_PIN = GPIO_PIN_5, SPI_MISO_GPIO = GPIOA, SPI_MISO_PIN = GPIO_PIN_6, SPI_MOSI_GPIO = GPIOA, SPI_MOSI_PIN = GPIO_PIN_7, USE_DMA = true, DMA_SPI_TX = DMA0, DMA_SPI_TX_CH = (dma_channel_enum)DMA_CH2 }
	Configuration parameters of the LCD Display class. More...

typedef enum Longan_nano::Display::_Config	Config
	Configuration parameters of the LCD Display class. More...

Private Types
enum	_Command { SETUP_NORMAL_MODE = 0xB1, SETUP_IDLE_MODE = 0xB2, SETUP_PARTIAL_MODE = 0xB3, DISPLAY_INVERSION_CONTROL = 0xB4, POWER_GVDD = 0xC0, POWER_VGH_VGL = 0xC1, POWER_VCOM1 = 0xC5, POWER_MODE_NORMAL = 0xC2, POWER_MODE_IDLE = 0xC3, POWER_MODE_PARTIAL = 0xC4, ADJUST_GAMMA_PLUS = 0xE0, ADJUST_GAMMA_MINUS = 0xE1, COLOR_FORMAT = 0x3A, MEMORY_DATA_ACCESS_CONTROL = 0x36, DISPLAY_ON = 0x29, SLEEP_OUT_BOOSTER_ON = 0x11, ENABLE_DISPLAY_INVERSION = 0x21, SEND_ROW_ADDRESS = 0x2A, SEND_COL_ADDRESS = 0x2B, WRITE_MEM = 0x2C, TERMINATOR = 0xFF }
	ST7735S Commands. More...

typedef enum Longan_nano::Display::_Command	Command
	ST7735S Commands. More...

typedef struct Longan_nano::Display::_Sprite	Sprite
	Sprite informations. More...

Private Member Functions
bool	init_gpio (void)
	Private init init_gpio \| void \|. More...

bool	init_spi (void)
	Private init init_spi \| void \|. More...

bool	init_dma (void)
	Private init init_dma \| void \|. More...

bool	init_st7735 (void)
	Private init init_st7735 \| void \|. More...

bool	is_spi_idle (void)
	Private HAL Method is_spi_idle \| void. More...

bool	is_spi_done_tx (void)
	Private HAL Method is_spi_done_tx \| void. More...

void	spi_wait_idle (void)
	Private HAL Method spi_wait_idle \| void. More...

void	spi_wait_tbe (void)
	Private HAL Method spi_wait_tbe \| void \|. More...

void	cs_active (void)
	Private HAL Method cs_active \| void \|. More...

void	cs_inactive (void)
	Private HAL Method cs_inactive \| void \|. More...

void	rs_mode_cmd (void)
	Private HAL Method rs_mode_cmd \| void \|. More...

void	rs_mode_data (void)
	Private HAL Method rs_mode_data \| void \|. More...

void	rst_active (void)
	Private HAL Method rst_active \| void \|. More...

void	rst_inactive (void)
	Private HAL Method rst_inactive \| void \|. More...

void	spi_set_8bit (void)
	Private HAL Method spi_set_8bit \| void \|. More...

void	spi_set_16bit (void)
	Private HAL Method spi_set_16bit \| void \|. More...

void	dma_send_map16 (uint16_t *data_ptr, uint16_t data_size)
	Private HAL Method dma_send_map16 \| uint16_t * \| uint16_t \|. More...

void	dma_send_solid16 (uint16_t *data_ptr, uint16_t data_size)
	Private HAL Method dma_send_map16 \| uint16_t * \| uint16_t \|. More...

Private Attributes
Sprite	g_sprite
	Runtime sprite informations. More...

uint16_t	g_address_buffer [2]
	Buffer to send address data using DMA. More...

uint32_t	g_sprite_status
	FSM status. More...

Static Private Attributes
static constexpr uint8_t	g_st7735s_init_sequence []
	ST7735S initialization sequence. Stored in flash memory. More...

Detailed Description

Longan Nano Display Driver.

Author: Orso Eric

Version: 2020-08-08

Copyright: BSD 3-Clause License (c) 2019-2020, Samuli Laine; BSD 3-Clause License (c) 2020, Orso Eric

Driver to use the embedded 160x80 0.96' LCD on the longan nano
SPI0 interface with physical screen
DMA0: executes a number of SPI0 transfers in background
Hardware display has a ST7735S controller
The driver is meant to accelerate sprite based drawing
Sprite buffer and draw are going to be handled by an higher level class
2020-07-07
Ported original LCD example to class. Basic operation. DMA doesn't work
2020-07-08
Skeletron for sprites
2020-07-10
Change architecture. S7735S_W160_H80_C16.hpp. Common name drive class: Display
With another display controller, Screen class and Display class interface remains the same
S7735S_W160_H80_C16.hpp is the specific lbrary for the physical display
Clean up, partition in a more intelligent way calls. Test project for driver only without sprites
2020-07-15
Tested draw with HAL builtin
2020-07-21
Found working DMA example from Samuli Laine https://github.com/slmisc/gd32v-lcd
2020-07-22
Transplant working driver function
Refactor function to use configuration and fit class form
set_sprite and update_sprite provide a non blocking draw method that hide the wait time
application can call update_sprite and immediately continue to do work while SPI and DMA are busy
update_sprite will immediately return without doing work if SPI or DMA are busy or if there is nothing to draw
2020-07-23
Clean up example
Prune excess methods from display class. Leave only the draw sprite primitives. Application is to be given control on resource utilization of the display
Refactor all calls to use configuration enum for the hardware peripherals
2020-07-24
Fixed color conversion function
2020-08-06
Massive update of style
Refactor functions, especially initialization
Full support for USE_DMA=false. screen updates much slower at the same CPU use
2020-08-07
Bugfix: Solid color draw was bugged

Member Typedef Documentation

◆ Command

typedef enum Longan_nano::Display::_Command Longan_nano::Display::Command

private

ST7735S Commands.

◆ Config

typedef enum Longan_nano::Display::_Config Longan_nano::Display::Config

protected

Configuration parameters of the LCD Display class.

◆ Sprite

typedef struct Longan_nano::Display::_Sprite Longan_nano::Display::Sprite

private

Sprite informations.

Member Enumeration Documentation

◆ _Command

enum Longan_nano::Display::_Command

private

ST7735S Commands.

Enumerator
SETUP_NORMAL_MODE
SETUP_IDLE_MODE
SETUP_PARTIAL_MODE
DISPLAY_INVERSION_CONTROL
POWER_GVDD
POWER_VGH_VGL
POWER_VCOM1
POWER_MODE_NORMAL
POWER_MODE_IDLE
POWER_MODE_PARTIAL
ADJUST_GAMMA_PLUS
ADJUST_GAMMA_MINUS
COLOR_FORMAT
MEMORY_DATA_ACCESS_CONTROL
DISPLAY_ON
SLEEP_OUT_BOOSTER_ON
ENABLE_DISPLAY_INVERSION
SEND_ROW_ADDRESS
SEND_COL_ADDRESS
WRITE_MEM
TERMINATOR

◆ _Config

enum Longan_nano::Display::_Config

protected

Configuration parameters of the LCD Display class.

Enumerator
WIDTH
HEIGHT
PIXEL_COUNT
COLOR_DEPTH
ROW_ADDRESS_OFFSET
COL_ADDRESS_OFFSET
RS_GPIO
RS_PIN
RST_GPIO
RST_PIN
RESET_DELAY
SPI_CH
SPI_CS_GPIO
SPI_CS_PIN
SPI_CLK_GPIO
SPI_CLK_PIN
SPI_MISO_GPIO
SPI_MISO_PIN
SPI_MOSI_GPIO
SPI_MOSI_PIN
USE_DMA
DMA_SPI_TX
DMA_SPI_TX_CH

Constructor & Destructor Documentation

◆ Display()

Longan_nano::Display::Display ( void )

constructor Display | void |

initialize display class
will NOT initialize the peripherals

◆ ~Display()

Longan_nano::Display::~Display ( void )

destructor ~Display | void |

Member Function Documentation

◆ clear() [1/2]

int Longan_nano::Display::clear ( uint16_t color )

inline

public method clear | void |

Parameters

color | uint16_t | clear the display to a solid color

Returns: int | number of pixels drawn

Clear the screen. Blocking method.
Draw a black sprite the size of the screen

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◆ clear() [2/2]

int Longan_nano::Display::clear ( void )

inline

public method clear | void |

Returns: int | number of pixels drawn

Clear the screen. Blocking method.
Draw a black sprite the size of the screen

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◆ color()

uint16_t Longan_nano::Display::color	(	uint8_t	r,
		uint8_t	g,
		uint8_t	b
	)

static

Public Method color | uint8_t | uint8_t | uint8_t |.

Parameters

r	\| uint8_t \| 8bit red color channel
g	\| uint8_t \| 8bit green color channel
b	\| uint8_t \| 8bit blue color channel

Returns: uint16_t | RGB565 color compatible with ST7735 display color space

convert from 24b 8R8G8B space to 16bit 5R6G5B space
RRRRRRRR
GGGGGGGG
BBBBBBBB
RRRRRGGGGGGBBBBB

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◆ cs_active()

void Longan_nano::Display::cs_active ( void )

inlineprivate

Private HAL Method cs_active | void |.

Select the ST7735 Display

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◆ cs_inactive()

void Longan_nano::Display::cs_inactive ( void )

inlineprivate

Private HAL Method cs_inactive | void |.

Deselect the ST7735 Display

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◆ dma_send_map16()

void Longan_nano::Display::dma_send_map16	(	uint16_t *	data_ptr,
		uint16_t	data_size
	)

inlineprivate

Private HAL Method dma_send_map16 | uint16_t * | uint16_t |.

Parameters

data_ptr	\| uint16_t * \| pointer to RGB565 pixel color map
data_size	\| uint16_t \| size of the pixel color map in pixels

Returns: void

Use the DMA to send a 16b memory through the SPI

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◆ dma_send_solid16()

void Longan_nano::Display::dma_send_solid16	(	uint16_t *	data_ptr,
		uint16_t	data_size
	)

inlineprivate

Private HAL Method dma_send_map16 | uint16_t * | uint16_t |.

Parameters

data_ptr	\| uint16_t * \| pointer to RGB565 solid color for the full sprite
data_size	\| uint16_t \| size of the pixel color map in pixels

Returns: void

Use the DMA to send a 16b data through the SPI a number of times

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◆ draw_sprite() [1/2]

int Longan_nano::Display::draw_sprite	(	int	origin_h,
		int	origin_w,
		int	size_h,
		int	size_w,
		uint16_t *	sprite_ptr
	)

public method draw_sprite | int | int | int | int | uint16_t * |

Parameters

origin_h	\| int \| starting top left corner height of the sprite
origin_w	\| int \| starting top left corner height of the sprite
size_h	\| int \| height size of the sprite
size_w	\| int \| width size of the sprite
sprite_ptr	\| uint16_t * \| pointer to RGB565 pixel color map

Returns: int | number of pixels drawn

Draw a sprite
Blocking method
Draw a color map, requires a user buffer of the proper size

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◆ draw_sprite() [2/2]

int Longan_nano::Display::draw_sprite	(	int	origin_h,
		int	origin_w,
		int	size_h,
		int	size_w,
		uint16_t	sprite_color
	)

public method draw_sprite | int | int | int | int | uint16_t |

Parameters

origin_h	\| int \| starting top left corner height of the sprite
origin_w	\| int \| starting top left corner height of the sprite
size_h	\| int \| height size of the sprite
size_w	\| int \| width size of the sprite
sprite_color	\| uint16_t \| RGB565 pixel solid color for the full sprite

Returns: int | number of pixels drawn

Draw a sprite
Blocking method
Draw a solid color sprite and doesn't require a color map

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◆ init()

bool Longan_nano::Display::init ( void )

Public init init | void |.

Returns: bool | false = OK | true = ERR

initialize the longan nano display and related peripherals

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◆ init_dma()

bool Longan_nano::Display::init_dma ( void )

inlineprivate

Private init init_dma | void |.

Returns: bool | false = OK | true = ERR

Initialize DMA that accelerates the SPI

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◆ init_gpio()

bool Longan_nano::Display::init_gpio ( void )

inlineprivate

Private init init_gpio | void |.

Returns: bool | false = OK | true = ERR

HAL method
initialize GPIO configuration

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◆ init_spi()

bool Longan_nano::Display::init_spi ( void )

inlineprivate

Private init init_spi | void |.

Returns: bool | false = OK | true = ERR

HAL method
Initialize SPI that communicates with the Display

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◆ init_st7735()

bool Longan_nano::Display::init_st7735 ( void )

private

Private init init_st7735 | void |.

Returns: bool | false = OK | true = ERR

Send initialization sequence to the ST7735 display controller
First byte in the sequence is command
Next bytes in the sequence are terminators
If the command is a terminator, it means the initialization sequence is complete

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◆ is_spi_done_tx()

bool Longan_nano::Display::is_spi_done_tx ( void )

inlineprivate

Private HAL Method is_spi_done_tx | void.

Returns: bool | false = BUSY | true = IDLE

return true when the SPI is done TX

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◆ is_spi_idle()

bool Longan_nano::Display::is_spi_idle ( void )

inlineprivate

Private HAL Method is_spi_idle | void.

Returns: bool | false = BUSY | true = IDLE

return true when the SPI is IDLE

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◆ register_sprite() [1/2]

int Longan_nano::Display::register_sprite	(	int	origin_h,
		int	origin_w,
		int	size_h,
		int	size_w,
		uint16_t *	sprite_ptr
	)

public method register_sprite | int | int | int | int | uint16_t * |

Parameters

origin_h	\| int \| starting top left corner height of the sprite
origin_w	\| int \| starting top left corner height of the sprite
size_h	\| int \| height size of the sprite
size_w	\| int \| width size of the sprite
sprite_ptr	\| uint16_t * \| pointer to RGB565 pixel color map

Returns: int | number of pixels queued for draw

Ask the driver to draw a sprite
The draw method handles sprites that fill only part of the screen
If reworked, the buffer stays the same or is smaller than user buffer
1) Sprite fully inside screen area: the sprite is queued for draw
2) Sprite is fully outside screen area: no pixels are queued for draw
3) sprite is partially outside screen area: the method rework the buffer to include only pixel that can be drawn

Todo:: handle partial sprite draw

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◆ register_sprite() [2/2]

int Longan_nano::Display::register_sprite	(	int	origin_h,
		int	origin_w,
		int	size_h,
		int	size_w,
		uint16_t	sprite_color
	)

public method register_sprite | int | int | int | int | uint16_t |

Parameters

origin_h	\| int \| starting top left corner height of the sprite
origin_w	\| int \| starting top left corner height of the sprite
size_h	\| int \| height size of the sprite
size_w	\| int \| width size of the sprite
sprite_color	\| uint16_t \| RGB565 pixel solid color for the full sprite

Returns: int | number of pixels queued for draw

Ask the driver to draw a sprite with a solid color
The draw method handles sprites that fill only part of the screen
If reworked, the buffer stays the same or is smaller than user buffer
1) Sprite fully inside screen area: the sprite is queued for draw
2) Sprite is fully outside screen area: no pixels are queued for draw
3) sprite is partially outside screen area: the method rework the buffer to include only pixel that can be drawn

Todo:: handle partial sprite draw

◆ rs_mode_cmd()

void Longan_nano::Display::rs_mode_cmd ( void )

inlineprivate

Private HAL Method rs_mode_cmd | void |.

Send a command to the display

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◆ rs_mode_data()

void Longan_nano::Display::rs_mode_data ( void )

inlineprivate

Private HAL Method rs_mode_data | void |.

Send data to the display

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◆ rst_active()

void Longan_nano::Display::rst_active ( void )

inlineprivate

Private HAL Method rst_active | void |.

Assert the reset pin of the physical display
The display will need time to become ready after an assert

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◆ rst_inactive()

void Longan_nano::Display::rst_inactive ( void )

inlineprivate

Private HAL Method rst_inactive | void |.

Deassert the reset pin of the physical display

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◆ spi_set_16bit()

void Longan_nano::Display::spi_set_16bit ( void )

inlineprivate

Private HAL Method spi_set_16bit | void |.

Configure the SPI to 16b

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◆ spi_set_8bit()

void Longan_nano::Display::spi_set_8bit ( void )

inlineprivate

Private HAL Method spi_set_8bit | void |.

Configure the SPI to 8b

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◆ spi_wait_idle()

void Longan_nano::Display::spi_wait_idle ( void )

inlineprivate

Private HAL Method spi_wait_idle | void.

Block execution until SPI is IDLE

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◆ spi_wait_tbe()

void Longan_nano::Display::spi_wait_tbe ( void )

inlineprivate

Private HAL Method spi_wait_tbe | void |.

Block execution until SPI is done TX

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◆ update_sprite()

bool Longan_nano::Display::update_sprite ( void )

public method update_sprite | void |

Returns: bool | false = IDLE | true = BUSY

Execute a step of the FSM that interfaces with the physical display
Handle both solid color and color map
sprite data must already be valid before execution

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Member Data Documentation

◆ g_address_buffer

uint16_t Longan_nano::Display::g_address_buffer[2]

private

Buffer to send address data using DMA.

◆ g_sprite

Sprite Longan_nano::Display::g_sprite

private

Runtime sprite informations.

◆ g_sprite_status

uint32_t Longan_nano::Display::g_sprite_status

private

FSM status.

◆ g_st7735s_init_sequence

constexpr uint8_t Longan_nano::Display::g_st7735s_init_sequence[]

staticconstexprprivate

Initial value:

=
        {
            Command::ENABLE_DISPLAY_INVERSION,      Command::TERMINATOR,
            Command::SETUP_NORMAL_MODE,             0x05, 0x3a, 0x3a, Command::TERMINATOR,
            Command::SETUP_IDLE_MODE,               0x05, 0x3a, 0x3a, Command::TERMINATOR,
            Command::SETUP_PARTIAL_MODE,            0x05, 0x3a, 0x3a, 0x05, 0x3a, 0x3a, Command::TERMINATOR,
            Command::DISPLAY_INVERSION_CONTROL,     0x03, Command::TERMINATOR,
            Command::POWER_GVDD,                    0x62, 0x02, 0x04, Command::TERMINATOR,
            Command::POWER_VGH_VGL,                 0xc0, Command::TERMINATOR,
            Command::POWER_MODE_NORMAL,             0x0d, 0x00, Command::TERMINATOR,
            Command::POWER_MODE_IDLE,               0x8d, 0x6a, Command::TERMINATOR,
            Command::POWER_MODE_PARTIAL,            0x8d, 0xee, Command::TERMINATOR,
            Command::POWER_VCOM1,                   0x0e, Command::TERMINATOR,
            Command::ADJUST_GAMMA_PLUS,             0x10, 0x0e, 0x02, 0x03, 0x0e, 0x07, 0x02, 0x07, 0x0a, 0x12, 0x27, 0x37, 0x00, 0x0d, 0x0e, 0x10, Command::TERMINATOR,
            Command::ADJUST_GAMMA_MINUS,            0x10, 0x0e, 0x03, 0x03, 0x0f, 0x06, 0x02, 0x08, 0x0a, 0x13, 0x26, 0x36, 0x00, 0x0d, 0x0e, 0x10, Command::TERMINATOR,
            Command::COLOR_FORMAT,                  0x55, Command::TERMINATOR,
            Command::MEMORY_DATA_ACCESS_CONTROL,    0x78, Command::TERMINATOR,
            Command::DISPLAY_ON,                    Command::TERMINATOR,
            Command::SLEEP_OUT_BOOSTER_ON,          Command::TERMINATOR,
            Command::TERMINATOR,
        }

ST7735S initialization sequence. Stored in flash memory.

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

src/ST7735S_W160_H80_C16.hpp

Classes

Public Member Functions

Static Public Member Functions

Protected Types

Private Types

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Typedef Documentation

◆ Command

◆ Config

◆ Sprite

Member Enumeration Documentation

◆ _Command

◆ _Config

Constructor & Destructor Documentation

◆ Display()

◆ ~Display()

Member Function Documentation

◆ clear() [1/2]

◆ clear() [2/2]

◆ color()

◆ cs_active()

◆ cs_inactive()

◆ dma_send_map16()

◆ dma_send_solid16()

◆ draw_sprite() [1/2]

◆ draw_sprite() [2/2]

◆ init()

◆ init_dma()

◆ init_gpio()

◆ init_spi()

◆ init_st7735()

◆ is_spi_done_tx()

◆ is_spi_idle()

◆ register_sprite() [1/2]

◆ register_sprite() [2/2]

◆ rs_mode_cmd()

◆ rs_mode_data()

◆ rst_active()

◆ rst_inactive()

◆ spi_set_16bit()

◆ spi_set_8bit()

◆ spi_wait_idle()

◆ spi_wait_tbe()

◆ update_sprite()

Member Data Documentation

◆ g_address_buffer

◆ g_sprite

◆ g_sprite_status

◆ g_st7735s_init_sequence