DisplayDriverParallel8< RGB_T > Class Template Reference

Common base class for 8-bit parallel ("Intel 8080"-style) TFT display drivers: 8 data lines (D0-D7), WR (write strobe), RD (read strobe, unused - this class only writes), RS/DC (command vs. data) and CS. This is the bus MCUFRIEND-style shields and many 40-pin parallel TFT breakout boards use, wired straight to 8 GPIOs rather than through SPI/QSPI - no dedicated bus peripheral is assumed, every data line and the WR strobe is bit-banged via digitalWrite(), the same portable approach TinyGPU/Input/TouchDriverArduino.h's TouchDriverBitBang uses for a resistive touch panel's four GPIO pins. This trades throughput (one digitalWrite() per bit, per byte) for working unmodified on any Arduino core - a hardware-accelerated 8080 driver (e.g. ESP32's LCD_CAM/ esp_lcd_panel_io_i80) would be faster but ties the implementation to one platform's peripheral, the same tradeoff DisplayDriverQSPI.h already makes explicitly for ESP32-only QSPI. More...

#include <DisplayDriverParallel8.h>

Inheritance diagram for DisplayDriverParallel8< RGB_T >:

Collaboration diagram for DisplayDriverParallel8< RGB_T >:

Public Member Functions
	DisplayDriverParallel8 (int8_t d0, int8_t d1, int8_t d2, int8_t d3, int8_t d4, int8_t d5, int8_t d6, int8_t d7, int8_t wr, int8_t dc, int8_t cs=-1, int8_t rd=-1, int8_t rst=-1, size_t xOffset=0, size_t yOffset=0, size_t width=240, size_t height=320)
size_t	width () const override
size_t	height () const override
bool	writeData (ISurface< RGB_T > &surface) override
bool	writeData (ISurface< RGB_T > &surface, size_t x, size_t y) override
Public Member Functions inherited from DisplayDriver< RGB_T >
virtual	~DisplayDriver ()=default
virtual bool	begin ()=0
virtual void	end ()
virtual bool	writeData (ISurface< RGB_T > &surface)=0
virtual bool	writeData (ISurface< RGB_T > &surface, size_t x, size_t y)=0
virtual void	setRotation (DisplayRotation rotation)
virtual size_t	width () const =0
virtual size_t	height () const =0
void	writeColor (size_t width, size_t height, RGB_T color)

Protected Member Functions
void	setColumnRowAddress (size_t x, size_t y, size_t w, size_t h)
bool	setAddressWindow (size_t x, size_t y, size_t w, size_t h) override
void	setupPinsAndReset ()
void	writeCommand (uint8_t cmd)
void	writeData16 (uint16_t d1, uint16_t d2)
void	writeData8 (uint8_t data)
void	writeDataN (std::initializer_list< uint8_t > bytes)
virtual bool	setAddressWindow (size_t x, size_t y, size_t w, size_t h)=0

Protected Attributes
int8_t	d_ [8]
int8_t	wr_
int8_t	dc_
int8_t	cs_
int8_t	rd_
int8_t	rst_
size_t	xOffset_
size_t	yOffset_
size_t	width_
size_t	height_
Protected Attributes inherited from DisplayDriver< RGB_T >
Font5x7< RGB_T >	defaultFont

Detailed Description

template<typename RGB_T = RGB565>
class tinygpu::DisplayDriverParallel8< RGB_T >

Common base class for 8-bit parallel ("Intel 8080"-style) TFT display drivers: 8 data lines (D0-D7), WR (write strobe), RD (read strobe, unused - this class only writes), RS/DC (command vs. data) and CS. This is the bus MCUFRIEND-style shields and many 40-pin parallel TFT breakout boards use, wired straight to 8 GPIOs rather than through SPI/QSPI - no dedicated bus peripheral is assumed, every data line and the WR strobe is bit-banged via digitalWrite(), the same portable approach TinyGPU/Input/TouchDriverArduino.h's TouchDriverBitBang uses for a resistive touch panel's four GPIO pins. This trades throughput (one digitalWrite() per bit, per byte) for working unmodified on any Arduino core - a hardware-accelerated 8080 driver (e.g. ESP32's LCD_CAM/ esp_lcd_panel_io_i80) would be faster but ties the implementation to one platform's peripheral, the same tradeoff DisplayDriverQSPI.h already makes explicitly for ESP32-only QSPI.

The command/parameter protocol on the wire (0x2A/0x2B/0x2C column/row/ RAM-write, 0x36 MADCTL, 0x3A pixel format, ...) is identical to the SPI wiring of the same controller families (see DisplayDriverSPI.h) - only how each command/data byte reaches the panel differs, so concrete drivers here mirror DisplayDriverSPI.h's ILI9341Driver/ST7789Driver/... init sequences byte-for-byte.

Constructor & Destructor Documentation

DisplayDriverParallel8()

DisplayDriverParallel8 ( int8_t  d0, int8_t  d1, int8_t  d2, int8_t  d3, int8_t  d4, int8_t  d5, int8_t  d6, int8_t  d7, int8_t  wr, int8_t  dc, int8_t  cs = -1, int8_t  rd = -1, int8_t  rst = -1, size_t  xOffset = 0, size_t  yOffset = 0, size_t  width = 240, size_t  height = 320  )

inline

Parameters

d0..d7	the 8 data lines, D0 = least significant bit.
wr	write-strobe pin: data is latched by the panel on WR's rising edge.
dc	data/command ("RS") select pin: LOW selects command, HIGH selects data - same polarity/role as DisplayDriverSPI's dc pin.
cs	chip-select pin, or -1 if the panel has CS permanently tied low (common on single-panel parallel shields).
rd	read-strobe pin, or -1 if unused - this class never reads from the panel, so it only needs to hold RD in its idle (HIGH, inactive) state so the panel doesn't drive the (shared, bidirectional on some boards) data bus back.
rst	reset pin, or -1 if not wired up (e.g. tied to the MCU's own reset).
width/height	the panel's addressable resolution, as reported by width()/height() - subclasses with a rotation concept (e.g. ILI9341Driver8080) override width()/height() themselves instead and can ignore these.

Member Function Documentation

height()

size_t height ( ) const

inlineoverridevirtual

Implements DisplayDriver< RGB_T >.

Reimplemented in ILI9341Driver8080< RGB_T >.

setAddressWindow()

bool setAddressWindow ( size_t  x, size_t  y, size_t  w, size_t  h  )

inlineoverrideprotectedvirtual

Implements DisplayDriver< RGB_T >.

setColumnRowAddress()

void setColumnRowAddress ( size_t  x, size_t  y, size_t  w, size_t  h  )

inlineprotected

setupPinsAndReset()

void setupPinsAndReset ( )

inlineprotected

width()

size_t width ( ) const

inlineoverridevirtual

Current addressable panel width/height in pixels - for a driver that supports setRotation(), these reflect the current rotation (landscape vs portrait swaps them; see isLandscapeFamily()), not necessarily the panel's native/physical orientation. Callers that need to lay out content (e.g. OutputTinyGPU's scale_to_fit target, or clearScreen()'s band loop) should read these fresh rather than caching their own copy, so a setRotation() call is picked up automatically without needing separate bookkeeping.

Implements DisplayDriver< RGB_T >.

Reimplemented in ILI9341Driver8080< RGB_T >.

writeCommand()

void writeCommand ( uint8_t  cmd )

inlineprotected

writeData() [1/2]

bool writeData ( ISurface< RGB_T > &  surface )

inlineoverridevirtual

Implements DisplayDriver< RGB_T >.

writeData() [2/2]

bool writeData ( ISurface< RGB_T > &  surface, size_t  x, size_t  y  )

inlineoverridevirtual

Implements DisplayDriver< RGB_T >.

writeData16()

void writeData16 ( uint16_t  d1, uint16_t  d2  )

inlineprotected

writeData8()

void writeData8 ( uint8_t  data )

inlineprotected

writeDataN()

void writeDataN ( std::initializer_list< uint8_t >  bytes )

inlineprotected

Writes each byte as a separate writeData8() call - a convenience for sending a command's multi-byte parameter list during init sequences, matching DisplayDriverSPI::writeDataN().

Member Data Documentation

cs_

int8_t cs_

protected

d_

int8_t d_[8]

protected

dc_

int8_t dc_

protected

height_

size_t height_

protected

rd_

int8_t rd_

protected

rst_

int8_t rst_

protected

width_

size_t width_

protected

wr_

int8_t wr_

protected

xOffset_

size_t xOffset_

protected

yOffset_

size_t yOffset_

protected

---

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

• src/TinyGPU/Drivers/DisplayDriverParallel8.h