Unit PiTFT28

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Description

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Adafruit PiTFT 2.8" LCD Driver unit

The Adafruit PiTFT 2.8" and PiTFT 3.2" LCD is a 320 x 240 pixel TFT with resistive touchscreen using an ILITEK ILI9340 driver and a STMicroelectronics STMPE610 resistive touchscreen controller. There is also a version available that includes a capacitive touchscreen using the Focaltech FT6236 controller.

This unit ties together the various components needed to make one of these boards work with Ultibo by finding the correct SPI or I2C device, creating the STMPE610 or FT6236 Touch device, creating the ILI9340 Framebuffer device and registering all of it with the correct parameters for the Adafruit board.

Details:

ILI9340

Width: 240

Height: 320

SPI Mode: 0

SPI Frequency: 32000000

SPI Chip Select: SPI_CS_0

DC GPIO: GPIO_PIN_25 (Pull: GPIO_PULL_NONE)

RST GPIO: GPIO_PIN_UNKNOWN

Backlight GPIO: GPIO_PIN_2 (STMPE GPIO)

STMPE (Resistive touch)

Chip: STMPE_CHIP_610

SPI Mode: 0

SPI Frequency: 500000

SPI Chip Select: SPI_CS_1

IRQ GPIO: GPIO_PIN_24 (Trigger: GPIO_TRIGGER_FALLING)(Pull: GPIO_PULL_UP)

FT6236 (Capacitive touch)

I2C Address: 0x38

IRQ GPIO: GPIO_PIN_24 (Trigger: GPIO_TRIGGER_FALLING)(Pull: GPIO_PULL_UP)

Switches

SW1 GPIO: GPIO_PIN_22

SW2 GPIO: GPIO_PIN_27

SW3 GPIO: GPIO_PIN_17

SW4 GPIO: GPIO_PIN_23

Constants

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PiTFT28 specific constants PITFT28_*

PITFT28_FRAMEBUFFER_DESCRIPTION = 'Adafruit PiTFT 2.8" LCD';	Description of PiTFT28 device
PITFT28_SIGNATURE = $AF000028;
PITFT28_SCREEN_WIDTH = 240;
PITFT28_SCREEN_HEIGHT = 320;

PiTFT28 GPIO PITFT28_LCD_*

PITFT28_LCD_DC = GPIO_PIN_25;
PITFT28_TOUCH_IRQ = GPIO_PIN_24;
NAPITFT28_LCD_BL = GPIO_PIN_2;	STMPE GPIO

Type definitions

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PiTFT28 specific types

PPiTFT28LCD = ^TPiTFT28LCD;

TPiTFT28LCD = record

Signature:LongWord;	Signature for entry validation
Rotation:LongWord;	Framebuffer rotation (eg FRAMEBUFFER_ROTATION_180)
SPI:PSPIDevice;	SPI device for this display
GPIO:PGPIODevice;	GPIO device for this display
Touch:PTouchDevice;	Touch (STMPE) device for this display
Backlight:PGPIODevice;	Backlight GPIO (STMPE) device for this display
Framebuffer:PFramebufferDevice;	Framebuffer (ILI9340) device for this display

Public variables

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PiTFT28 specific variables

PITFT28_SPI_DEVICE:String = 'SPI0';

PITFT28_LCD_CHIPSELECT:Word = SPI_CS_0;

PITFT28_TOUCH_CHIPSELECT:Word = SPI_CS_1;

Function declarations

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Initialization functions

procedure PiTFT28Init;

Description: Initialize the PiTFT28 unit and parameters

Note	Called only during system startup

function PiTFT28Start(Rotation:LongWord; const Device:String; DisplaySelect,TouchSelect:Word):THandle;

Description: Start the PiTFT28 driver and register the Touch, Backlight (GPIO) and Framebuffer devices associated with the display

Rotation	The rotation of the display (eg FRAMEBUFFER_ROTATION_180)
Device	The SPI device that the ILI9340 and STMPE610 devices are connected to
DisplaySelect	The SPI chip select of the ILI9340 LCD controller
TouchSelect	The SPI chip select of the STMPE610 touch controller
Return	The handle of the PiTFT28 on success or INVALID_HANDLE_VALUE on failure
Note	This function will be called during startup if the parameter PITFT28_AUTOSTART is True Can be called multiple times to support more than one PiTFT LCD display

function PiTFT28Stop(Handle:THandle):Boolean;

Description: Stop the PiTFT28 driver and deregister the Touch, Backlight (GPIO) and Framebuffer devices associated with the display

Handle	The handle of the PiTFT28 or INVALID_HANDLE_VALUE for the default display
Return	True if completed or False on failure

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