Unit PiTFT28

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Description


Adafruit PiTFT 2.8" LCD Driver unit

The Adafruit PiTFT 2.8" LCD is a 320 x 240 pixel TFT with resistive touchscreen using an ILITEK ILI9340 driver and a STMicroelectronics STMPE811 resistive touchscreen controller.

This unit ties together the various components needed to make one of these boards work with Ultibo by finding the correct SPI device, creating the STMPE811 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

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)

Switches

SW1 GPIO: GPIO_PIN_22

SW2 GPIO: GPIO_PIN_27

SW3 GPIO: GPIO_PIN_17

SW4 GPIO: GPIO_PIN_23

Constants



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



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



PiTFT28 specific variables

PITFT28_SPI_DEVICE:String = 'SPI0';
PITFT28_LCD_CHIPSELECT:Word = SPI_CS_0;
PITFT28_TOUCH_CHIPSELECT:Word = SPI_CS_1;


Function declarations



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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