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lcd.c
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lcd.c
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#include <tm4c123gh6pm.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include "lcd.h"
#define HIGH (db & 0xF0)
#define LOW ((db & 0x0F) << 4)
#define E (1u << 2) //PD2
#define RW (1u << 1) //PD1
#define RS 1u //PD0
#define DB4 (1u << 4) //PC4
#define DB5 (1u << 5) //PC5
#define DB6 (1u << 6) //PC6
#define DB7 (1u << 7) //PC7
void init_PORTS()
{
unsigned long volatile delay;
SYSCTL_RCGCGPIO_R |= (SYSCTL_RCGC2_GPIOD | SYSCTL_RCGC2_GPIOC); //Enable clock for PORTD and PORTC
delay = SYSCTL_RCGC2_R;
GPIO_PORTC_DIR_R = (DB4 | DB5 | DB6 | DB7); //Set specified pins as output
GPIO_PORTD_DIR_R |= (RS | RW | E); //Set specified pins as output
GPIO_PORTC_DEN_R = (DB4 | DB5 | DB6 | DB7);
GPIO_PORTD_DEN_R |= (RS | RW | E); //Digital enable specified pins
}
void delay_ms(float value)
{
double ms = value * 16000;
NVIC_ST_CTRL_R = 0; /* (1) disable SysTick during setup */
NVIC_ST_RELOAD_R = ms - 1; /* (2) number of counts to wait */
NVIC_ST_CURRENT_R = 0; /* (3) any value written to CURRENT clears */
NVIC_ST_CTRL_R |= 0x5; /* (4) enable SysTick with core clock */
while ((NVIC_ST_CTRL_R & 0x00010000) == 0)
{
; /* wait for COUNT flag */
}
}
void lcd_enable()
{
GPIO_PORTD_DATA_BITS_R[E] = E;
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = ~E;
}
void lcd_data(unsigned char db)
{
delay_ms(0.100);
GPIO_PORTD_DATA_R = 0b00000001; //RS =1, E=0, RW=0 == Write data mode
GPIO_PORTC_DATA_R = HIGH;
lcd_enable();
GPIO_PORTC_DATA_R = LOW;
lcd_enable();
}
void lcd_instr(unsigned char db)
{
delay_ms(0.100);
GPIO_PORTD_DATA_R = 0x00; //RS =0, E=0, RW=0 == Write Instruction mode
GPIO_PORTC_DATA_R = HIGH; //Send HIGH to databus
lcd_enable();
GPIO_PORTC_DATA_R = LOW; //Send LOW to databus
lcd_enable();
}
void lcd_write_graphics(const unsigned char *image)
{
unsigned char x, y;
for (y = 0; y < 64; y++)
{
if (y < 32)
{
lcd_instr(SET_GRAM_ADDR | y);
lcd_instr(0x80);
}
else
{
lcd_instr(SET_GRAM_ADDR | (y - 32));
lcd_instr(0x88);
}
for (x = 0; x < 8; x++)
{
lcd_data(image[x * 2 + 16 * y]);
lcd_data(image[x * 2 + 1 + 16 * y]);
}
}
}
void lcd_fill_screen_graphics(unsigned char fill_value)
{
unsigned char x, y;
for (y = 0; y < 64; y++)
{
if (y < 32)
{
lcd_instr(SET_GRAM_ADDR | y);
lcd_instr(0x80);
}
else
{
lcd_instr(SET_GRAM_ADDR | (y - 32));
lcd_instr(0x88);
}
for (x = 0; x < 8; x++)
{
lcd_data(fill_value);
lcd_data(fill_value);
}
}
}
unsigned char lcd_read_byte(unsigned char addr_y, unsigned char addr_x)
{
unsigned char byte = 0;
lcd_instr(SET_GRAM_ADDR | addr_y);
lcd_instr(SET_GRAM_ADDR | addr_x);
GPIO_PORTC_DIR_R &= ~(DB4 | DB5 | DB6 | DB7);
GPIO_PORTD_DATA_BITS_R[RW] = RW;
GPIO_PORTD_DATA_BITS_R[RS] = RS;
////////after address set to read, dummy read(unless another read_byte issued)
////Dummy read
//get upper 4 bits
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = E;
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = ~E;
//get lower 4bits
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = E;
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = ~E;
////Dummy read end
//get upper 4 bits
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = E;
byte = GPIO_PORTC_DATA_R & 0xF0;
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = ~E;
//get lower 4bits
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = E;
byte |= (GPIO_PORTC_DATA_R & 0xF0) >> 4;
delay_ms(0.002);
GPIO_PORTD_DATA_BITS_R[E] = ~E;
GPIO_PORTD_DATA_BITS_R[RW] = ~RW;
GPIO_PORTD_DATA_BITS_R[RS] = ~RS;
GPIO_PORTC_DIR_R |= (DB4 | DB5 | DB6 | DB7);
return byte;
}
void init_DISPLAY()
{
delay_ms(50);
//Function Set 4 bit
lcd_instr(FUNCTION_SET_4BIT | BASIC);
delay_ms(0.120);
//again
lcd_instr(FUNCTION_SET_4BIT | BASIC);
delay_ms(0.120);
//Display on off control
lcd_instr(DISPLAY_STATUS | DISPLAY_ON | CURSOR_OFF | BLINK_OFF);
delay_ms(0.120);
//Display Clear
lcd_instr(DISPLAY_CLEAR);
delay_ms(12);
//Entry mode set
lcd_instr(ENTRY_MODESET | AC_INCREASE);
delay_ms(0.080);
}
void init_DISPLAY_GRAPHICS()
{
delay_ms(50);
//Function Set 4 bit
lcd_instr(FUNCTION_SET_4BIT | BASIC);
delay_ms(0.120);
//again
lcd_instr(FUNCTION_SET_4BIT | BASIC);
delay_ms(0.120);
//Display on off control
lcd_instr(DISPLAY_STATUS | DISPLAY_ON | CURSOR_OFF | BLINK_OFF);
delay_ms(0.120);
//Display Clear
lcd_instr(DISPLAY_CLEAR);
delay_ms(12);
//Entry mode set
lcd_instr(ENTRY_MODESET | AC_INCREASE);
delay_ms(0.080);
//Display on off control
lcd_instr(DISPLAY_STATUS | DISPLAY_ON | CURSOR_OFF | BLINK_OFF);
delay_ms(0.080);
//Display Clear
lcd_instr(DISPLAY_CLEAR);
delay_ms(10);
//Entry mode set
lcd_instr(ENTRY_MODESET | AC_INCREASE);
delay_ms(0.080);
//Select Extended mode set
lcd_instr(FUNCTION_SET_4BIT | EXTENDED);
delay_ms(0.120);
//Graphics Display On
lcd_instr(FUNCTION_SET_4BIT | EXTENDED | G_DISPLAY_ON);
delay_ms(0.120);
lcd_fill_screen_graphics(0x00);
}