📄 lcd_4bit.c
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/******************************************************************************/
/* LCD_4BIT.C: Functions for 2 line 16 character Text LCD (4-bit interface) */
/* connected on MCBSTM32 evaluation board */
/******************************************************************************/
/* This file is part of the uVision/ARM development tools. */
/* Copyright (c) 2005-2007 Keil Software. All rights reserved. */
/* This software may only be used under the terms of a valid, current, */
/* end user licence from KEIL for a compatible version of KEIL software */
/* development tools. Nothing else gives you the right to use this software. */
/******************************************************************************/
#include <stm32f10x_lib.h> /* STM32F10x Library Definitions */
#include <stdio.h>
#include "LCD.h"
/*********************** Hardware specific configuration **********************/
/*------------------------- Speed dependant settings -------------------------*/
/* If processor works on high frequency delay has to be increased, it can be
increased by factor 2^N by this constant */
#define DELAY_2N 0
/*------------------------- Text LCD size definitions ------------------------*/
#define LineLen 16 /* Width (in characters) */
#define NumLines 2 /* Hight (in lines) */
/*-------------------- LCD interface hardware definitions --------------------*/
/* PINS:
- DB4 = PC3
- DB5 = PC2
- DB6 = PC1
- DB7 = PC0
- E = PC10
- RW = PC11
- RS = PC12 */
#define PIN_E ( 1 << 8)
#define PIN_RW ( 1 << 15)
#define PIN_RS ( 1 << 7)
//#define PINS_CTRL (0x07 << 10)
#define PINS_DATA (0xF0 << 0)
//#define PINS_ALL (PINS_CTRL | PINS_DATA)
const unsigned int SWAP_DATA[16] = { 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,
0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF};
/* Enable Clock for peripheral driving LCD pins */
#define LCD_CLOCK_EN RCC_APB2PeriphClockCmd (RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOD|RCC_APB2Periph_GPIOE, ENABLE);
/* pin E setting to 0 or 1 */
#define LCD_E(x) GPIOA->ODR = (GPIOA->ODR & ~PIN_E) | (x ? PIN_E : 0);
/* pin RW setting to 0 or 1 */
#define LCD_RW(x) GPIOD->ODR = (GPIOD->ODR & ~PIN_RW) | (x ? PIN_RW : 0);
/* pin RS setting to 0 or 1 */
#define LCD_RS(x) GPIOD->ODR = (GPIOD->ODR & ~PIN_RS) | (x ? PIN_RS : 0);
/* Reading DATA pins */
#define LCD_DATA_IN SWAP_DATA[(((GPIOE->IDR & PINS_DATA) >> 4) & 0x0F)]
/* Writing value to DATA pins */
//#define LCD_DATA_OUT(x) GPIOE->ODR = (GPIOE->ODR & ~PINS_DATA) | ((SWAP_DATA[x]) << 4);
#define LCD_DATA_OUT(x) GPIOE->ODR = (GPIOE->ODR & ~PINS_DATA) | (((SWAP_DATA[x]) << 4));
/* Setting all pins to output mode */
//#define LCD_ALL_DIR_OUT GPIOC->CRL = (GPIOC->CRL & 0xFFFF0000) | 0x00003333; \
// GPIOC->CRH = (GPIOC->CRH & 0xFFF000FF) | 0x00033300;
#define LCD_ALL_DIR_OUT GPIOA->CRL = (GPIOA->CRL & 0xFFF00000) | 0x00033333; \
GPIOA->CRH = (GPIOA->CRH & 0xFFFF0000) | 0x00003333; \
GPIOD->CRL = (GPIOD->CRL & 0x00000000) | 0x33333333; \
GPIOD->CRH = (GPIOD->CRH & 0x00000000) | 0x33333333; \
GPIOE->CRL = (GPIOE->CRL & 0x00000000) | 0x33333333; \
GPIOE->CRH = (GPIOE->CRH & 0x00000000) | 0x33333333;
/* Setting DATA pins to input mode */
//#define LCD_DATA_DIR_IN GPIOC->CRL = (GPIOC->CRL & 0xFFFF0000) | 0x00004444;
#define LCD_DATA_DIR_IN GPIOE->CRL = (GPIOE->CRL & 0x00000000) | 0x44444444;
/* Setting DATA pins to output mode */
//#define LCD_DATA_DIR_OUT GPIOC->CRL = (GPIOC->CRL & 0xFFFF0000) | 0x00003333;
#define LCD_DATA_DIR_OUT GPIOE->CRL = (GPIOE->CRL & 0x00000000) | 0x33333333;
/******************************************************************************/
/* 8 user defined characters to be loaded into CGRAM (used for bargraph) */
const char UserFont[8][8] = {
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
{ 0x10,0x10,0x10,0x10,0x10,0x10,0x10,0x10 },
{ 0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18 },
{ 0x1C,0x1C,0x1C,0x1C,0x1C,0x1C,0x1C,0x1C },
{ 0x1E,0x1E,0x1E,0x1E,0x1E,0x1E,0x1E,0x1E },
{ 0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F },
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }
};
/************************ Global function definitions *************************/
/*******************************************************************************
* Delay in while loop cycles *
* Parameter: cnt: number of while cycles to delay *
* Return: *
*******************************************************************************/
static void delay (int cnt)
{
cnt <<= DELAY_2N;
while (cnt--);
}
/*******************************************************************************
* Read status of LCD controller *
* Parameter: none *
* Return: Status byte contains busy flag and address pointer *
*******************************************************************************/
static unsigned char lcd_read_status (void)
{
unsigned char status;
LCD_DATA_DIR_IN
LCD_RS(0)
LCD_RW(1)
delay(10);
LCD_E(1)
delay(10);
status = LCD_DATA_IN << 4;
LCD_E(0)
delay(10);
LCD_E(1)
delay(10);
status |= LCD_DATA_IN;
LCD_E(0)
LCD_DATA_DIR_OUT
return (status);
}
/*******************************************************************************
* Wait until LCD controller busy flag is 0 *
* Parameter: *
* Return: Status byte of LCD controller (busy + address) *
*******************************************************************************/
static unsigned char wait_while_busy (void)
{
unsigned char status;
do {
status = lcd_read_status();
} while (status & 0x80); /* Wait for busy flag */
return (status);
}
/*******************************************************************************
* Write 4-bits to LCD controller *
* Parameter: c: command to be written *
* Return: *
*******************************************************************************/
void lcd_write_4bit (unsigned char c)
{
LCD_RW(0)
LCD_E(1)
LCD_DATA_OUT(c&0x0F)
delay(10);
LCD_E(0)
delay(10);
}
/*******************************************************************************
* Write command to LCD controller *
* Parameter: c: command to be written *
* Return: *
*******************************************************************************/
void lcd_write_cmd (unsigned char c)
{
wait_while_busy();
LCD_RS(0)
lcd_write_4bit (c>>4);
lcd_write_4bit (c);
}
/*******************************************************************************
* Write data to LCD controller *
* Parameter: c: data to be written *
* Return: *
*******************************************************************************/
static void lcd_write_data (unsigned char c)
{
wait_while_busy();
LCD_RS(1)
lcd_write_4bit (c>>4);
lcd_write_4bit (c);
}
/*******************************************************************************
* Print Character to current cursor position *
* Parameter: c: character to be printed *
* Return: *
*******************************************************************************/
void lcd_putchar (char c)
{
lcd_write_data (c);
}
/*******************************************************************************
* Initialize the LCD controller *
* Parameter: *
* Return: *
*******************************************************************************/
void lcd_init (void)
{
int i;
char const *p;
LCD_CLOCK_EN /* Enable clock for peripheral */
/* Set all pins for LCD as outputs */
LCD_ALL_DIR_OUT
delay (15000);
LCD_RS(0)
lcd_write_4bit (0x3); /* Select 4-bit interface */
delay (4100);
lcd_write_4bit (0x3);
delay (100);
lcd_write_4bit (0x3);
lcd_write_4bit (0x2);
lcd_write_cmd (0x28); /* 2 lines, 5x8 character matrix */
lcd_write_cmd (0x0C); /* Display ctrl:Disp=ON,Curs/Blnk=OFF */
lcd_write_cmd (0x06); /* Entry mode: Move right, no shift */
/* Load user-specific characters into CGRAM */
lcd_write_cmd(0x40); /* Set CGRAM address counter to 0 */
p = &UserFont[0][0];
for (i = 0; i < sizeof(UserFont); i++, p++)
lcd_putchar (*p);
lcd_write_cmd(0x80); /* Set DDRAM address counter to 0 */
}
/*******************************************************************************
* Set cursor position on LCD display *
* Parameter: column: column position *
* line: line position *
* Return: *
*******************************************************************************/
void set_cursor (int column, int line)
{
unsigned char address;
address = (line * 40) + column;
address = 0x80 + (address & 0x7F);
lcd_write_cmd(address); /* Set DDRAM address counter to 0 */
}
/*******************************************************************************
* Clear the LCD display *
* Parameter: *
* Return: *
*******************************************************************************/
void lcd_clear (void)
{
lcd_write_cmd(0x01); /* Display clear */
set_cursor (0, 0);
}
/*******************************************************************************
* Print sting to LCD display *
* Parameter: string: pointer to output string *
* Return: *
*******************************************************************************/
void lcd_print (char *string)
{
while (*string) {
lcd_putchar (*string++);
}
}
/*******************************************************************************
* Display bargraph on LCD display *
* Parameter: pos_x: horizontal position of bargraph start *
* pos_y: vertical position of bargraph *
* value: size of bargraph active field (in pixels) *
* Return: *
*******************************************************************************/
void lcd_bargraph (int pos_x, int pos_y, int value) {
int i;
set_cursor (pos_x, pos_y);
for (i = 0; i < 16; i++) {
if (value > 5) {
lcd_putchar (0x05);
value -= 5;
} else {
lcd_putchar (value);
while (i++ < 16) lcd_putchar (0);
}
}
}
/******************************************************************************/
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