glcd_lowlevel.c File Reference

#include "glcd_lowlevel.h"
#include "glcd_types.h"
#include <LPC17xx.h>

Go to the source code of this file.

Macros
#define	PIN_EN   (1 << 19)
	LCD Controller PINs are connected to the GPIO0 port (same as the LEDs). Hence, they're controlled using the FIOSET and FIOCLR registers.
#define	PIN_LE   (1 << 20)
#define	PIN_DIR   (1 << 21)
#define	PIN_CS   (1 << 22)
#define	PIN_RS   (1 << 23)
#define	PIN_WR   (1 << 24)
#define	PIN_RD   (1 << 25)
#define	LCD_EN(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_EN) : (LPC_GPIO0->FIOCLR = PIN_EN))
#define	LCD_LE(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_LE) : (LPC_GPIO0->FIOCLR = PIN_LE))
#define	LCD_DIR(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_DIR) : (LPC_GPIO0->FIOCLR = PIN_DIR))
#define	LCD_CS(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_CS) : (LPC_GPIO0->FIOCLR = PIN_CS))
#define	LCD_RS(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_RS) : (LPC_GPIO0->FIOCLR = PIN_RS))
#define	LCD_WR(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_WR) : (LPC_GPIO0->FIOCLR = PIN_WR))
#define	LCD_RD(x)   ((x) ? (LPC_GPIO0->FIOSET = PIN_RD) : (LPC_GPIO0->FIOCLR = PIN_RD))
#define	DELAY_COUNT(count)
#define	DELAY_MS(ms)

Enumerations
enum	LCDModel {   ILI9320 , ILI9325 , ILI9328 , ILI9331 ,   SSD1298 , SSD1289 , ST7781 , LGDP4531 ,   SPFD5408B , R61505U , HX8346A , HX8347D ,   HX8347A , LGDP4535 , SSD2119 }
	Models. More...

Functions
_PRIVATE void	send (u16 halfw)
	Writes an half-word (16 bits) into the LCD's DB port.
_PRIVATE u16	recv (void)
	Reads an half-word (16 bits) from the LCD's DB port.
_PRIVATE void	init_rw_operation_at (u16 index)
	Tells the LCD controller to initiate a R/W operation with the register at the index specified.
_PRIVATE void	do_write (u16 data)
	Writes an half-word (16 bits) into the LCD's DB port, destined to the register at the index selected with the previous call to init_ro_operation_at.
_PRIVATE u16	do_read (void)
	Reads an half-word (16 bits) from the LCD's DB port, from the register at the index selected with the previous call to init_ro_operation_at.
_PRIVATE void	write_to (u16 reg, u16 data)
	Writes a 16-bit value to the LCD controller, at the specified register.
_PRIVATE u16	read_from (u16 reg)
	Reads an HW from the LCD controller, at the specified register.
_PRIVATE void	set_gram_cursor (u16 x, u16 y)
	Sets the GRAM cursor to the specified coordinates, for writing data into the appropriate pixel in the display.
void	__LCD_LL_Init (u16 orientation)
u16	__LCD_LL_GetPointColor (u16 x, u16 y)
void	__LCD_LL_SetPointColor (u16 rgb565, u16 x, u16 y)
void	__LCD_LL_FillScreen (u16 color)

Variables
_PRIVATE u8	s_model_code
	The model code of the LCD controller.
_PRIVATE u16	s_orientation
	The current orientation of the screen.
_DECL_EXTERNALLY u16	LCDMaxX
	The maximum X and Y coordinates of the screen.
_DECL_EXTERNALLY u16	LCDMaxY

Macro Definition Documentation

DELAY_COUNT

#define DELAY_COUNT

(

count

)

Definition at line 40 of file glcd_lowlevel.c.

DELAY_MS

#define DELAY_MS

(

ms

)

Definition at line 41 of file glcd_lowlevel.c.

LCD_CS

#define LCD_CS

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_CS) : (LPC_GPIO0->FIOCLR = PIN_CS))

Definition at line 28 of file glcd_lowlevel.c.

LCD_DIR

#define LCD_DIR

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_DIR) : (LPC_GPIO0->FIOCLR = PIN_DIR))

Definition at line 27 of file glcd_lowlevel.c.

LCD_EN

#define LCD_EN

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_EN) : (LPC_GPIO0->FIOCLR = PIN_EN))

Definition at line 25 of file glcd_lowlevel.c.

LCD_LE

#define LCD_LE

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_LE) : (LPC_GPIO0->FIOCLR = PIN_LE))

Definition at line 26 of file glcd_lowlevel.c.

LCD_RD

#define LCD_RD

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_RD) : (LPC_GPIO0->FIOCLR = PIN_RD))

Definition at line 31 of file glcd_lowlevel.c.

LCD_RS

#define LCD_RS

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_RS) : (LPC_GPIO0->FIOCLR = PIN_RS))

Definition at line 29 of file glcd_lowlevel.c.

LCD_WR

#define LCD_WR

(

x

)

((x) ? (LPC_GPIO0->FIOSET = PIN_WR) : (LPC_GPIO0->FIOCLR = PIN_WR))

Definition at line 30 of file glcd_lowlevel.c.

PIN_CS

#define PIN_CS   (1 << 22)

Definition at line 20 of file glcd_lowlevel.c.

PIN_DIR

#define PIN_DIR   (1 << 21)

Definition at line 19 of file glcd_lowlevel.c.

PIN_EN

#define PIN_EN   (1 << 19)

LCD Controller PINs are connected to the GPIO0 port (same as the LEDs). Hence, they're controlled using the FIOSET and FIOCLR registers.

EN = Enable (19)

LE = Latch Enable (20)

DIR = Bus Direction (21) (0 = Write, 1 = Read)

CS = Chip Select (22)

RS = Register Select (23) (0 = Command, 1 = Data)

WR = Write Operation (24)

RD = Read Operation (25)

Definition at line 17 of file glcd_lowlevel.c.

PIN_LE

#define PIN_LE   (1 << 20)

Definition at line 18 of file glcd_lowlevel.c.

PIN_RD

#define PIN_RD   (1 << 25)

Definition at line 23 of file glcd_lowlevel.c.

PIN_RS

#define PIN_RS   (1 << 23)

Definition at line 21 of file glcd_lowlevel.c.

PIN_WR

#define PIN_WR   (1 << 24)

Definition at line 22 of file glcd_lowlevel.c.

Enumeration Type Documentation

LCDModel

enum LCDModel

Models.

Enumerator
ILI9320
ILI9325
ILI9328
ILI9331
SSD1298
SSD1289
ST7781
LGDP4531
SPFD5408B
R61505U
HX8346A
HX8347D
HX8347A
LGDP4535
SSD2119

Definition at line 47 of file glcd_lowlevel.c.

{
    ILI9320,   // 0x9320
    ILI9325,   // 0x9325
    ILI9328,   // 0x9328
    ILI9331,   // 0x9331
    SSD1298,   // 0x8999
    SSD1289,   // 0x8989
    ST7781,    // 0x7783
    LGDP4531,  // 0x4531
    SPFD5408B, // 0x5408
    R61505U,   // 0x1505 0x0505
    HX8346A,   // 0x0046
    HX8347D,   // 0x0047
    HX8347A,   // 0x0047
    LGDP4535,  // 0x4535
    SSD2119    // 3.5 LCD 0x9919
};

Function Documentation

__LCD_LL_FillScreen()

void __LCD_LL_FillScreen

(

u16

color

)

Definition at line 374 of file glcd_lowlevel.c.

{
    // Sets the GRAM cursor to the top-left corner of the display
    if (s_model_code == HX8347D || s_model_code == HX8347A)
    {
        write_to(0x02, 0x00);
        write_to(0x03, 0x00);
        write_to(0x04, 0x00);
        write_to(0x05, 0xEF);
        write_to(0x06, 0x00);
        write_to(0x07, 0x00);
        write_to(0x08, 0x01);
        write_to(0x09, 0x3F);
    }
    else
        set_gram_cursor(0, 0);
 
    init_rw_operation_at(0x0022); // Write GRAM
    for (u32 index = 0; index < LCDMaxX * LCDMaxY; index++)
        do_write(color & 0xFFFF);
}

__LCD_LL_GetPointColor()

u16 __LCD_LL_GetPointColor	(	u16	x,
		u16	y
	)

Definition at line 334 of file glcd_lowlevel.c.

{
    u16 dummy;
 
    set_gram_cursor(x, y);
    init_rw_operation_at(0x0022); // Write GRAM
 
    switch (s_model_code)
    {
    case ST7781:
    case LGDP4531:
    case LGDP4535:
    case SSD1289:
    case SSD1298:
        dummy = do_read(); /* Empty read */
        dummy = do_read();
        return dummy;
    case HX8347A:
    case HX8347D: {
        dummy = do_read(); /* Empty read */
 
        const u8 red = do_read() >> 3;
        const u8 green = do_read() >> 2;
        const u8 blue = do_read() >> 3;
        dummy = (u16)((red << 11) | (green << 5) | blue);
        return dummy;
    }
    default:               /* 0x9320 0x9325 0x9328 0x9331 0x5408 0x1505 0x0505 0x9919 */
        dummy = do_read(); /* Empty read */
        dummy = do_read();
        return dummy;
    }
}

__LCD_LL_Init()

void __LCD_LL_Init

(

u16

orientation

)

Definition at line 228 of file glcd_lowlevel.c.

{
    // Setting PINS as 00 (GPIO) in PINSEL0 (bit 6 to 25) for P0.19 to P0.25
    // 0000 0011 1111 1111 1111 1111 1100 0000
    LPC_PINCON->PINSEL1 &= ~(0x03FFFFC0);
 
    // Setting 00 in PINSEL4 (bit 0 to 15) for P2.0 to P2.7
    // 0000 0000 0000 0000 1111 1111 1111 1111
    LPC_PINCON->PINSEL4 &= ~(0x0000FFFF);
 
    /* EN = P0.19 , LE = P0.20 , DIR = P0.21 , CS = P0.22 , RS = P0.23 , RS = P0.23 */
    /* RS = P0.23 , WR = P0.24 , RD = P0.25 , DB[0.7] = P2.0...P2.7 , DB[8.15]= P2.0...P2.7 */
    LPC_GPIO0->FIODIR |= 0x03f80000;
    LPC_GPIO0->FIOSET = 0x03f80000;
 
    s_orientation = orientation;
    if (orientation == LCD_ORIENT_VER || orientation == LCD_ORIENT_VER_INV)
    {
        LCDMaxX = 240;
        LCDMaxY = 320;
    }
    else
    {
        LCDMaxX = 320;
        LCDMaxY = 240;
    }
 
    DELAY_MS(100);
    const u16 code = read_from(0x0000);
    if (code == 0x9325 || code == 0x9328)
    {
        s_model_code = ILI9325;
        write_to(0x00e7, 0x0010); // Test Register
        write_to(0x0000, 0x0001); // Starts internal OSC
        write_to(0x0001, 0x0100); // Output driver control
 
        write_to(0x0002, 0x0700);                                     // LCD Driver Waveform Control
        write_to(0x0003, (1 << 12) | (1 << 5) | (1 << 4) | (0 << 3)); // Entry mode
        write_to(0x0004, 0x0000);                                     // Resizing Function
        write_to(0x0008, 0x0207);                                     // Back and Front porch periods
        write_to(0x0009, 0x0000);                                     // Non-Display Area refresh cycle
        write_to(0x000a, 0x0000);                                     // Frame cycle
        write_to(0x000c, 0x0001);
        write_to(0x000d, 0x0000);
        write_to(0x000f, 0x0000);
 
        // Power Control
        write_to(0x0010, 0x0000);
        write_to(0x0011, 0x0007);
        write_to(0x0012, 0x0000);
        write_to(0x0013, 0x0000);
        DELAY_MS(50);
        write_to(0x0010, 0x1590);
        write_to(0x0011, 0x0227);
        DELAY_MS(50);
        write_to(0x0012, 0x009c);
        DELAY_MS(50);
        write_to(0x0013, 0x1900);
        write_to(0x0029, 0x0023);
 
        write_to(0x002b, 0x000e); // Frate rate & Color control
        DELAY_MS(50);
        write_to(0x0020, 0x0000); // GRAM horizontal Address
        write_to(0x0021, 0x0000); // GRAM Vertical Address
 
        DELAY_MS(50);
        write_to(0x0030, 0x0007);
        write_to(0x0031, 0x0707);
        write_to(0x0032, 0x0006);
        write_to(0x0035, 0x0704);
        write_to(0x0036, 0x1f04);
        write_to(0x0037, 0x0004);
        write_to(0x0038, 0x0000);
        write_to(0x0039, 0x0706);
        write_to(0x003c, 0x0701);
        write_to(0x003d, 0x000f);
        DELAY_MS(50);
        write_to(0x0050, 0x0000);
        write_to(0x0051, 0x00ef);
        write_to(0x0052, 0x0000);
        write_to(0x0053, 0x013f);
        write_to(0x0060, 0xa700);
        write_to(0x0061, 0x0001);
        write_to(0x006a, 0x0000);
        write_to(0x0080, 0x0000);
        write_to(0x0081, 0x0000);
        write_to(0x0082, 0x0000);
        write_to(0x0083, 0x0000);
        write_to(0x0084, 0x0000);
        write_to(0x0085, 0x0000);
        write_to(0x0090, 0x0010);
        write_to(0x0092, 0x0000);
        write_to(0x0093, 0x0003);
        write_to(0x0095, 0x0110);
        write_to(0x0097, 0x0000);
        write_to(0x0098, 0x0000);
 
        // Display On Sequence
        write_to(0x0007, 0x0133);
        write_to(0x0020, 0x0000);
        write_to(0x0021, 0x0000);
    }
 
    DELAY_MS(50);
}

__LCD_LL_SetPointColor()

void __LCD_LL_SetPointColor	(	u16	rgb565,
		u16	x,
		u16	y
	)

Definition at line 368 of file glcd_lowlevel.c.

{
    set_gram_cursor(x, y);
    write_to(0x0022, rgb565 & 0xFFFF);
}

do_read()

_PRIVATE u16 do_read

(

void

)

Reads an half-word (16 bits) from the LCD's DB port, from the register at the index selected with the previous call to init_ro_operation_at.

Returns

The HW read.

Note

Before calling this function, init_rw_operation_at must be called to select the register to read from.

Definition at line 154 of file glcd_lowlevel.c.

{
    LCD_CS(0);
    LCD_RS(1);
    LCD_WR(1);
    LCD_RD(0);
    const u16 value = recv();
    LCD_RD(1);
    LCD_CS(1);
    return value;
}

do_write()

_PRIVATE void do_write

(

u16

data

)

Writes an half-word (16 bits) into the LCD's DB port, destined to the register at the index selected with the previous call to init_ro_operation_at.

Parameters

data	The HW to write.

Note

Before calling this function, init_rw_operation_at must be called to select the register to write to.

Definition at line 137 of file glcd_lowlevel.c.

{
    LCD_CS(0);
    LCD_RS(1);
    send(data);
    LCD_WR(0);
    DELAY_COUNT(1);
    LCD_WR(1);
    LCD_CS(1);
}

init_rw_operation_at()

_PRIVATE void init_rw_operation_at

(

u16

index

)

Tells the LCD controller to initiate a R/W operation with the register at the index specified.

Parameters

index

The index of the register to read/write.

Definition at line 118 of file glcd_lowlevel.c.

{
    LCD_CS(0);
    LCD_RS(0);
    LCD_RD(1);
    send(index);
    DELAY_COUNT(22);
    LCD_WR(0);
    DELAY_COUNT(1);
    LCD_WR(1);
    LCD_CS(1);
}

read_from()

_PRIVATE u16 read_from

(

u16

reg

)

Reads an HW from the LCD controller, at the specified register.

Parameters

reg	The register to read from.

Returns

The HW.

Definition at line 178 of file glcd_lowlevel.c.

{
    init_rw_operation_at(reg);
    return do_read();
}

recv()

_PRIVATE u16 recv ( void  )

inline

Reads an half-word (16 bits) from the LCD's DB port.

Returns

The HW read.

Definition at line 98 of file glcd_lowlevel.c.

{
    u16 value;
 
    LPC_GPIO2->FIODIR &= ~(0xFF);              /* P2.0...P2.7 Input */
    LCD_DIR(0);                                /* Interface B->A */
    LCD_EN(0);                                 /* Enable 2B->2A */
    DELAY_COUNT(30);                           /* delay some times */
    value = LPC_GPIO2->FIOPIN0;                /* Read D8..D15 */
    LCD_EN(1);                                 /* Enable 1B->1A */
    DELAY_COUNT(30);                           /* delay some times */
    value = (value << 8) | LPC_GPIO2->FIOPIN0; /* Read D0..D7 */
    LCD_DIR(1);
 
    return value;
}

send()

_PRIVATE void send ( u16  halfw )

inline

Writes an half-word (16 bits) into the LCD's DB port.

Parameters

byte	The HW to write.

Note

Writing to DB requires a specific sequence of operations, timed based on the specific protocol.

DB[7..0] and DB[15..8] are connected to the same pins 2.[0..7].

Definition at line 85 of file glcd_lowlevel.c.

{
    LPC_GPIO2->FIODIR |= 0xFF; /* P2.0...P2.7 Output */
    LCD_DIR(1);                /* Interface A->B */
    LCD_EN(0);                 /* Enable 2A->2B */
    LPC_GPIO2->FIOPIN = halfw; /* Write D0..D7 */
    LCD_LE(1);
    LCD_LE(0);                      /* latch D0..D7 */
    LPC_GPIO2->FIOPIN = halfw >> 8; /* Write D8..D15 */
}

set_gram_cursor()

_PRIVATE void set_gram_cursor	(	u16	x,
		u16	y
	)

Sets the GRAM cursor to the specified coordinates, for writing data into the appropriate pixel in the display.

Parameters

x	The X coordinate (column).
y	The Y coordinate (row).

Definition at line 188 of file glcd_lowlevel.c.

{
    if (s_orientation == LCD_ORIENT_HOR || s_orientation == LCD_ORIENT_HOR_INV)
    {
        // Swap X and Y if orientation is 90 or 270 degrees
        u16 tmp = x;
        x = y;
        y = (LCDMaxX - 1) - tmp;
    }
 
    switch (s_model_code)
    {
    default:                 /* 0x9320 0x9325 0x9328 0x9331 0x5408 0x1505 0x0505 0x7783 0x4531 0x4535 */
        write_to(0x0020, x); // 0x20 = GRAM Address Set (Horizontal Address)
        write_to(0x0021, y); // 0x21 = GRAM Address Set (Vertical Address)
        break;
 
    case SSD1298: /* 0x8999 */
    case SSD1289: /* 0x8989 */
        write_to(0x004e, x);
        write_to(0x004f, y);
        break;
 
    case HX8346A: /* 0x0046 */
    case HX8347A: /* 0x0047 */
    case HX8347D: /* 0x0047 */
        write_to(0x02, x >> 8);
        write_to(0x03, x);
 
        write_to(0x06, y >> 8);
        write_to(0x07, y);
        break;
 
    case SSD2119: /* 3.5 LCD 0x9919 */
        break;
    }
}

write_to()

_PRIVATE void write_to	(	u16	reg,
		u16	data
	)

Writes a 16-bit value to the LCD controller, at the specified register.

Parameters

reg	The register to write to.
data	The value to write.

Definition at line 169 of file glcd_lowlevel.c.

{
    init_rw_operation_at(reg);
    do_write(data);
}

Variable Documentation

LCDMaxX

_DECL_EXTERNALLY u16 LCDMaxX

The maximum X and Y coordinates of the screen.

Definition at line 75 of file glcd_lowlevel.c.

LCDMaxY

_DECL_EXTERNALLY u16 LCDMaxY

Definition at line 75 of file glcd_lowlevel.c.

s_model_code

_PRIVATE u8 s_model_code

The model code of the LCD controller.

Definition at line 69 of file glcd_lowlevel.c.

s_orientation

_PRIVATE u16 s_orientation

The current orientation of the screen.

Definition at line 72 of file glcd_lowlevel.c.