Gabi Allende: LCD Gráfico

Hola a todos, en esta práctica os voy a enseñar cómo escribir en un LCD gráfico, que nada tiene que ver con un alfanumérico, ya que el gráfico funciona a modo de mapa de bits, por lo que podemos dibujar a nuestro antojo, mientras que en el alfanumérico esta cuestión es imposible.

En primer lugar deciros que vamos a utilizar el famoso 18f4550 para controlarlo, y nos valdremos de diferentes librerías, que me vienen dentro del compilador CCSC, o “C compiler”

La parte importante de la práctica es desarrollar un conversor AD pero, como estamos usando un LCD gráfico vamos a aprovechar para dibujar cualquier cosa, bien sea líneas, círculos, etc.

Esto se verá más adelante. Por otro lado, es importante saber que nuestro LCD gráfico tiene una resolución de 128x64 y que, como ya dije sobre el LCD anterior, tiene un microcontrolador incorporado, el ks0108.

Gracias al uso de ciertas librerías, concretamente 2, la “HDM64GS12.c” y “graphics.c” podemos tener un mayor control del dispositivo, y mediante unas cuantas sentencias, podemos dibujar de una manera bastante sencilla.

Os diré que ambas librerías me venían en la ruta ““C:\Program Files\PICC\Drivers”, por si no la encontráis. Obviamente tenéis que tener C compiler instalado.

Aquí os adjunto las librerías:

En primer lugar la HDM64GS12.c

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

//// HDM64GS12.c ////

//// ////

//// This file contains drivers for using a Hantronix HDM64GS12 with ////

//// a KS0108 display controller. The HDM64GS12 is 128 by 64 pixels. ////

//// The driver treats the upper left pixel as (0,0). ////

//// ////

//// Use #define FAST_GLCD if the target chip has at least 1k of RAM ////

//// to decrease the time it takes to update the display. ////

//// glcd_update() must then be called to update the display after ////

//// changing the pixel information. ////

//// See ex_glcd.c for suggested usage. ////

//// See KS0108.c for controlling a single 64 by 64 display ////

/////////////////////////////////////////////////////////////////////////

//// ////

//// LCD Pin connections: ////

//// (These can be changed as needed in the following defines). ////

//// * 1: VSS is connected to GND ////

//// * 2: VDD is connected to +5V ////

//// * 3: V0 - LCD operating voltage (Constrast adjustment) ////

//// * 4: D/I - Data or Instruction is connected to B2 ////

//// * 5: R/W - Read or Write is connected to B4 ////

//// * 6: Enable is connected to B5 ////

//// *7-14: Data Bus 0 to 7 is connected to port d ////

//// *15: Chip Select 1 is connected to B0 ////

//// *16: Chip Select 2 is connected to B1 ////

//// *17: Reset is connected to C0 ////

//// *18: Negative voltage is also connected to the 20k Ohm POT ////

//// *19: Positive voltage for LED backlight is connected to +5V ////

//// *20: Negavtive voltage for LED backlight is connected to GND ////

//// ////

/////////////////////////////////////////////////////////////////////////

//// ////

//// glcd_init(mode) ////

//// * Must be called before any other function. ////

//// - mode can be ON or OFF to turn the LCD on or off ////

//// ////

//// glcd_pixel(x,y,color) ////

//// * Sets the pixel to the given color. ////

//// - color can be ON or OFF ////

//// ////

//// glcd_fillScreen(color) ////

//// * Fills the entire LCD with the given color. ////

//// - color can be ON or OFF ////

//// ////

//// glcd_update() ////

//// * Write the display data stored in RAM to the LCD ////

//// * Only available if FAST_GLCD is defined ////

//// ////

/////////////////////////////////////////////////////////////////////////

//// This source code may only be used by licensed users of the CCS ////

//// C compiler. This source code may only be distributed to other ////

//// licensed users of the CCS C compiler. No other use, ////

//// reproduction or distribution is permitted without written ////

//// permission. Derivative programs created using this software ////

//// in object code form are not restricted in any way. ////

/////////////////////////////////////////////////////////////////////////

#ifndef HDM64GS12

#define HDM64GS12

#ifndef GLCD_WIDTH

#define GLCD_WIDTH 128

#endif

#ifndef GLCD_CS1

#define GLCD_CS1 PIN_B0 // Chip Selection 1

#endif

#ifndef GLCD_CS2

#define GLCD_CS2 PIN_B1 // Chip Selection 2

#endif

#ifndef GLCD_DI

#define GLCD_DI PIN_B2 // Data or Instruction input

#endif

#ifndef GLCD_RW

#define GLCD_RW PIN_B4 // Read/Write

#endif

#ifndef GLCD_E

#define GLCD_E PIN_B5 // Enable

#endif

#ifndef GLCD_RST

#define GLCD_RST PIN_C0 // Reset

#endif

#define GLCD_LEFT 0

#define GLCD_RIGHT 1

#ifndef ON

#define ON 1

#endif

#ifndef OFF

#define OFF 0

#endif

/////////////////////////////////////////////////////////////////////////

// Function Prototypes

/////////////////////////////////////////////////////////////////////////

void glcd_init(int1 mode);

void glcd_pixel(int8 x, int8 y, int1 color);

void glcd_fillScreen(int1 color);

void glcd_writeByte(int1 side, BYTE data);

BYTE glcd_readByte(int1 side);

void glcd_update();

/////////////////////////////////////////////////////////////////////////

#ifdef FAST_GLCD

struct

{

int8 left[512];

int8 right[512];

} displayData;

#endif

// Purpose: Initialize the LCD.

// Call before using any other LCD function.

// Inputs: OFF - Turns the LCD off

// ON - Turns the LCD on

void glcd_init(int1 mode)

{

// Initialze some pins

output_high(GLCD_RST);

output_low(GLCD_E);

output_low(GLCD_CS1);

output_low(GLCD_CS2);

output_low(GLCD_DI); // Set for instruction

glcd_writeByte(GLCD_LEFT, 0xC0); // Specify first RAM line at the top

glcd_writeByte(GLCD_RIGHT, 0xC0); // of the screen

glcd_writeByte(GLCD_LEFT, 0x40); // Set the column address to 0

glcd_writeByte(GLCD_RIGHT, 0x40);

glcd_writeByte(GLCD_LEFT, 0xB8); // Set the page address to 0

glcd_writeByte(GLCD_RIGHT, 0xB8);

if(mode == ON)

{

glcd_writeByte(GLCD_LEFT, 0x3F); // Turn the display on

glcd_writeByte(GLCD_RIGHT, 0x3F);

}

else

{

glcd_writeByte(GLCD_LEFT, 0x3E); // Turn the display off

glcd_writeByte(GLCD_RIGHT, 0x3E);

}

glcd_fillScreen(OFF); // Clear the display

#ifdef FAST_GLCD

glcd_update();

#endif

}

// Purpose: Update the LCD with data from the display arrays

#ifdef FAST_GLCD

void glcd_update()

{

int8 i, j;

int8 *p1, *p2;

p1 = displayData.left;

p2 = displayData.right;

// Loop through the vertical pages

for(i = 0; i < 8; ++i)

{

output_low(GLCD_DI); // Set for instruction

glcd_writeByte(GLCD_LEFT, 0x40); // Set horizontal address to 0

glcd_writeByte(GLCD_RIGHT, 0x40);

glcd_writeByte(GLCD_LEFT, i | 0xB8); // Set page address

glcd_writeByte(GLCD_RIGHT, i | 0xB8);

output_high(GLCD_DI); // Set for data

// Loop through the horizontal sections

for(j = 0; j < 64; ++j)

{

glcd_writeByte(GLCD_LEFT, *p1++); // Turn pixels on or off

glcd_writeByte(GLCD_RIGHT, *p2++); // Turn pixels on or off

}

#endif

// Purpose: Turn a pixel on a graphic LCD on or off

// Inputs: 1) x - the x coordinate of the pixel

// 2) y - the y coordinate of the pixel

// 3) color - ON or OFF

void glcd_pixel(int8 x, int8 y, int1 color)

#ifdef FAST_GLCD

{

int8* p;

int16 temp;

temp = y/8;

temp *= 64;

temp += x;

if(x > 63)

{

p = displayData.right + temp - 64;

}

else

{

p = displayData.left + temp;

}

if(color)

{

bit_set(*p, y%8);

}

else

{

bit_clear(*p, y%8);

}

#else

{

BYTE data;

int1 side = GLCD_LEFT; // Stores which chip to use on the LCD

if(x > 63) // Check for first or second display area

{

x -= 64;

side = GLCD_RIGHT;

}

output_low(GLCD_DI); // Set for instruction

bit_clear(x,7); // Clear the MSB. Part of an instruction code

bit_set(x,6); // Set bit 6. Also part of an instruction code

glcd_writeByte(side, x); // Set the horizontal address

glcd_writeByte(side, (y/8 & 0xBF) | 0xB8); // Set the vertical page address

output_high(GLCD_DI); // Set for data

glcd_readByte(side); // Need two reads to get data

data = glcd_readByte(side); // at new address

if(color == ON)

bit_set(data, y%8); // Turn the pixel on

else // or

bit_clear(data, y%8); // turn the pixel off

output_low(GLCD_DI); // Set for instruction

glcd_writeByte(side, x); // Set the horizontal address

output_high(GLCD_DI); // Set for data

glcd_writeByte(side, data); // Write the pixel data

}

#endif

// Purpose: Fill the LCD screen with the passed in color

// Inputs: ON - turn all the pixels on

// OFF - turn all the pixels off

void glcd_fillScreen(int1 color)

#ifdef FAST_GLCD

{

int8 data;

int8 *p1, *p2;

int16 i;

p1 = displayData.left;

p2 = displayData.right;

data = 0xFF * color;

for(i=0; i<512; ++i)

{

*p1++ = data;

*p2++ = data;

}

#else

{

int8 i, j;

// Loop through the vertical pages

for(i = 0; i < 8; ++i)

{

output_low(GLCD_DI); // Set for instruction

glcd_writeByte(GLCD_LEFT, 0b01000000); // Set horizontal address to 0

glcd_writeByte(GLCD_RIGHT, 0b01000000);

glcd_writeByte(GLCD_LEFT, i | 0b10111000);// Set page address

glcd_writeByte(GLCD_RIGHT, i | 0b10111000);

output_high(GLCD_DI); // Set for data

// Loop through the horizontal sections

for(j = 0; j < 64; ++j)

{

glcd_writeByte(GLCD_LEFT, 0xFF*color); // Turn pixels on or off

glcd_writeByte(GLCD_RIGHT, 0xFF*color); // Turn pixels on or off

}

#endif

// Purpose: Write a byte of data to the specified chip

// Inputs: 1) chipSelect - which chip to write the data to

// 2) data - the byte of data to write

void glcd_writeByte(int1 side, BYTE data)

{

if(side) // Choose which side to write to

output_high(GLCD_CS2);

else

output_high(GLCD_CS1);

output_low(GLCD_RW); // Set for writing

output_d(data); // Put the data on the port

delay_cycles(1);

output_high(GLCD_E); // Pulse the enable pin

delay_cycles(5);

output_low(GLCD_E);

output_low(GLCD_CS1); // Reset the chip select lines

output_low(GLCD_CS2);

}

// Purpose: Reads a byte of data from the specified chip

// Ouputs: A byte of data read from the chip

BYTE glcd_readByte(int1 side)

{

BYTE data; // Stores the data read from the LCD

set_tris_d(0xFF); // Set port d to input

output_high(GLCD_RW); // Set for reading

if(side) // Choose which side to write to

output_high(GLCD_CS2);

else

output_high(GLCD_CS1);

delay_cycles(1);

output_high(GLCD_E); // Pulse the enable pin

delay_cycles(4);

data = input_d(); // Get the data from the display's output register

output_low(GLCD_E);

output_low(GLCD_CS1); // Reset the chip select lines

output_low(GLCD_CS2);

return data; // Return the read data

}

#endif

Y en segundo lugar la librería “graphics.c”

/////////////////////////////////////////////////////////////////////////

//// graphics.c ////

//// ////

//// This file contains functions to draw lines, rectangles, bars, ////

//// circles and text to a display. A function which draws a ////

//// single pixel must be defined before calling the functions in ////

//// this file. Call it glcd_pixel(x, y, color) where x is the ////

//// horizontal coordinate, y is the vertical coordinate, and ////

//// color is 1 bit to turn the pixel on or off. ////

//// ////

//// * Note: (0, 0) is treated as the upper left corner ////

//// ////

/////////////////////////////////////////////////////////////////////////

//// ////

//// glcd_line(x1, y1, x2, y2, color) ////

//// * Draws a line from the first point to the second point ////

//// with the given color ////

//// - color can be ON or OFF ////

//// ////

//// glcd_rect(x1, y1, x2, y2, fill, color) ////

//// * Draws a rectangle with one corner at point (x1,y1) and ////

//// the other corner at point (x2,y2) ////

//// - fill can be YES or NO ////

//// - color can be ON or OFF ////

//// ////

//// glcd_bar(x1, y1, x2, y2, width, color) ////

//// * Draws a bar (wide line) from the first point to the ////

//// second point ////

//// - width is the number of pixels wide ////

//// - color is ON or OFF ////

//// ////

//// glcd_circle(x, y, radius, fill, color) ////

//// * Draws a circle with center at (x,y) ////

//// - fill can be YES or NO ////

//// - color can be ON or OFF ////

//// ////

//// glcd_text57(x, y, textptr, size, color) ////

//// * Write the null terminated text pointed to by textptr with ////

//// the upper left coordinate of the first character at (x,y) ////

//// Characters are 5 pixels wide and 7 pixels tall ////

//// - size is an integer that scales the size of the text ////

//// - color is ON or OFF ////

//// * Note - This function wraps characters to the next line ////

//// use #define GLCD_WIDTH to specify a display width ////