Collin J. Doering
435c8eb07b
Inspired by http://web.alfredstate.edu/weimandn/programming/lcd/ATmega328/LCD_code_index.html. Forgot about the 'data hold time', 'address hold time' and 'enable cycle time'. These delays should eventually be implemented as preprocessor constants. Signed-off-by: Collin J. Doering <collin.doering@rekahsoft.ca>
374 lines
10 KiB
C
374 lines
10 KiB
C
/**
|
|
* (C) Copyright Collin J. Doering 2015
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/**
|
|
* File: lcdLib.c
|
|
* Author: Collin J. Doering <collin.doering@rekahsoft.ca>
|
|
* Date: Sep 29, 2015
|
|
*/
|
|
|
|
#include <util/delay.h>
|
|
|
|
// Include header
|
|
#include "lcdLib.h"
|
|
|
|
// Globals
|
|
volatile uint8_t currentLineNum = 0;
|
|
volatile uint8_t currentLineChars = 0;
|
|
|
|
const uint8_t lineBeginnings[LCD_NUMBER_OF_LINES] = { LCD_LINE_BEGINNINGS };
|
|
|
|
//------------------------------------------------------------------------------------------
|
|
|
|
// Function definitions
|
|
void flashLED(uint8_t times) {
|
|
while (times > 0) {
|
|
STATUS_LED_PORT |= 1 << STATUS_LED; // turn on status LED
|
|
_delay_ms(100);
|
|
STATUS_LED_PORT &= ~(1 << STATUS_LED); // turn status LED off
|
|
_delay_ms(100);
|
|
times--;
|
|
}
|
|
}
|
|
|
|
//------------------------------------
|
|
|
|
void clkLCD(void) {
|
|
LCD_ENABLE_PORT |= (1 << LCD_ENABLE);
|
|
_delay_us(LCD_ENABLE_HIGH_DELAY);
|
|
LCD_ENABLE_PORT &= ~(1 << LCD_ENABLE);
|
|
_delay_us(LCD_ENABLE_LOW_DELAY);
|
|
}
|
|
|
|
void loop_until_LCD_BF_clear(void) {
|
|
uint8_t bf;
|
|
|
|
LCD_RS_PORT &= ~(1 << LCD_RS); // RS=0
|
|
LCD_RW_PORT |= (1 << LCD_RW); // RW=1
|
|
|
|
// Set LCD_BF as input
|
|
LCD_DBUS7_DDR &= ~(1 << LCD_BF);
|
|
|
|
STATUS_LED_PORT |= 1 << STATUS_LED; // DEBUG
|
|
do {
|
|
bf = 0;
|
|
LCD_ENABLE_PORT |= (1 << LCD_ENABLE);
|
|
_delay_us(1); // 'delay data time' and 'enable pulse width'
|
|
|
|
bf |= (LCD_DBUS7_PIN & (1 << LCD_BF));
|
|
|
|
LCD_ENABLE_PORT &= ~(1 << LCD_ENABLE);
|
|
_delay_us(1); // 'address hold time', 'data hold time' and 'enable cycle width'
|
|
|
|
#ifdef FOUR_BIT_MODE
|
|
LCD_ENABLE_PORT |= (1 << LCD_ENABLE);
|
|
_delay_us(1); // 'delay data time' and 'enable pulse width'
|
|
LCD_ENABLE_PORT &= ~(1 << LCD_ENABLE);
|
|
_delay_us(1); // 'address hold time', 'data hold time' and 'enable cycle width'
|
|
#endif
|
|
} while (bf);
|
|
STATUS_LED_PORT &= ~(1 << STATUS_LED); // DEBUG
|
|
|
|
#if defined (FOUR_BIT_MODE) || defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
|
|
LCD_DBUS7_DDR |= (1 << LCD_DBUS7);
|
|
LCD_DBUS6_DDR |= (1 << LCD_DBUS6);
|
|
LCD_DBUS5_DDR |= (1 << LCD_DBUS5);
|
|
LCD_DBUS4_DDR |= (1 << LCD_DBUS4);
|
|
#ifdef EIGHT_BIT_ARBITRARY_PIN_MODE
|
|
LCD_DBUS3_DDR |= (1 << LCD_DBUS3);
|
|
LCD_DBUS2_DDR |= (1 << LCD_DBUS2);
|
|
LCD_DBUS1_DDR |= (1 << LCD_DBUS1);
|
|
LCD_DBUS0_DDR |= (1 << LCD_DBUS0);
|
|
#endif
|
|
#else
|
|
LCD_DBUS_DDR = 0xff; // Reset all LCD_DBUS_PORT pins as outputs
|
|
#endif
|
|
}
|
|
|
|
#ifdef FOUR_BIT_MODE
|
|
/*
|
|
Writes one nibble to the LCD data bus. Does not touch the RS or RW control lines.
|
|
Note: the bits that are sent are the four MSBs of the given argument
|
|
*/
|
|
void writeLCDNibble_(uint8_t b) {
|
|
// Reset data lines to zeros
|
|
LCD_DBUS7_PORT &= ~(1 << LCD_DBUS7);
|
|
LCD_DBUS6_PORT &= ~(1 << LCD_DBUS6);
|
|
LCD_DBUS5_PORT &= ~(1 << LCD_DBUS5);
|
|
LCD_DBUS4_PORT &= ~(1 << LCD_DBUS4);
|
|
|
|
// Write 1's where appropriate on data lines
|
|
if (b & (1 << 7)) LCD_DBUS7_PORT |= (1 << LCD_DBUS7);
|
|
if (b & (1 << 6)) LCD_DBUS6_PORT |= (1 << LCD_DBUS6);
|
|
if (b & (1 << 5)) LCD_DBUS5_PORT |= (1 << LCD_DBUS5);
|
|
if (b & (1 << 4)) LCD_DBUS4_PORT |= (1 << LCD_DBUS4);
|
|
|
|
// Pulse the enable line
|
|
clkLCD();
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
Write a byte to the LCD data bus. Does not touch the RS or RW control lines.
|
|
*/
|
|
void writeLCDByte_(uint8_t b) {
|
|
#ifdef FOUR_BIT_MODE
|
|
writeLCDNibble_(b);
|
|
writeLCDNibble_(b << 4);
|
|
#elif defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
|
|
// Reset data lines to zeros
|
|
LCD_DBUS7_PORT &= ~(1 << LCD_DBUS7);
|
|
LCD_DBUS6_PORT &= ~(1 << LCD_DBUS6);
|
|
LCD_DBUS5_PORT &= ~(1 << LCD_DBUS5);
|
|
LCD_DBUS4_PORT &= ~(1 << LCD_DBUS4);
|
|
LCD_DBUS3_PORT &= ~(1 << LCD_DBUS3);
|
|
LCD_DBUS2_PORT &= ~(1 << LCD_DBUS2);
|
|
LCD_DBUS1_PORT &= ~(1 << LCD_DBUS1);
|
|
LCD_DBUS0_PORT &= ~(1 << LCD_DBUS0);
|
|
|
|
// Write 1's where appropriate on data lines
|
|
if (b & (1 << 7)) LCD_DBUS7_PORT |= (1 << LCD_DBUS7);
|
|
if (b & (1 << 6)) LCD_DBUS6_PORT |= (1 << LCD_DBUS6);
|
|
if (b & (1 << 5)) LCD_DBUS5_PORT |= (1 << LCD_DBUS5);
|
|
if (b & (1 << 4)) LCD_DBUS4_PORT |= (1 << LCD_DBUS4);
|
|
if (b & (1 << 3)) LCD_DBUS3_PORT |= (1 << LCD_DBUS3);
|
|
if (b & (1 << 2)) LCD_DBUS2_PORT |= (1 << LCD_DBUS2);
|
|
if (b & (1 << 1)) LCD_DBUS1_PORT |= (1 << LCD_DBUS1);
|
|
if (b & (1 << 0)) LCD_DBUS0_PORT |= (1 << LCD_DBUS0);
|
|
|
|
clkLCD();
|
|
#else
|
|
LCD_DBUS_PORT = b;
|
|
clkLCD();
|
|
#endif
|
|
}
|
|
|
|
void writeLCDInstr_(uint8_t instr) {
|
|
LCD_RS_PORT &= ~(1 << LCD_RS); // RS=0
|
|
LCD_RW_PORT &= ~(1 << LCD_RW); // RW=0
|
|
|
|
#ifdef FOUR_BIT_MODE
|
|
writeLCDNibble_(instr);
|
|
writeLCDNibble_(instr << 4);
|
|
#else
|
|
writeLCDByte_(instr);
|
|
#endif
|
|
}
|
|
|
|
void writeLCDInstr(uint8_t instr) {
|
|
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
|
|
writeLCDInstr_(instr);
|
|
}
|
|
|
|
void writeCharToLCD_(char c) {
|
|
LCD_RS_PORT |= (1 << LCD_RS); // RS=1
|
|
LCD_RW_PORT &= ~(1 << LCD_RW); // RW=0
|
|
|
|
#ifdef FOUR_BIT_MODE
|
|
writeLCDNibble_(c);
|
|
writeLCDNibble_(c << 4);
|
|
#else
|
|
writeLCDByte_(c);
|
|
#endif
|
|
}
|
|
|
|
void writeCharToLCD(char c) {
|
|
loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions
|
|
writeCharToLCD_(c);
|
|
}
|
|
|
|
void writeStringToLCD(const char* str) {
|
|
while (*str != '\0') {
|
|
switch (*str) {
|
|
case '\n': // Go to next line on screen
|
|
if (currentLineNum == LCD_NUMBER_OF_LINES - 1) {
|
|
clearDisplay();
|
|
} else {
|
|
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
|
|
currentLineChars = 0;
|
|
}
|
|
break;
|
|
;
|
|
default:
|
|
if (currentLineChars == LCD_CHARACTERS_PER_LINE) {
|
|
if (currentLineNum == LCD_NUMBER_OF_LINES - 1) {
|
|
clearDisplay();
|
|
} else {
|
|
writeLCDInstr(INSTR_DDRAM_ADDR | lineBeginnings[++currentLineNum]);
|
|
currentLineChars = 0;
|
|
}
|
|
}
|
|
writeCharToLCD(*str);
|
|
currentLineChars++;
|
|
;
|
|
}
|
|
|
|
str++;
|
|
}
|
|
}
|
|
|
|
void clearDisplay(void) {
|
|
writeLCDInstr(CMD_CLEAR_DISPLAY);
|
|
|
|
// Reset line and char number tracking
|
|
currentLineNum = 0;
|
|
currentLineChars = 0;
|
|
}
|
|
|
|
void returnHome(void) {
|
|
writeLCDInstr(CMD_RETURN_HOME);
|
|
|
|
// Reset line and char number tracking
|
|
currentLineNum = 0;
|
|
currentLineChars = 0;
|
|
}
|
|
|
|
/* char readCharFromLCD(void) { */
|
|
/* loop_until_LCD_BF_clear(); // Wait until LCD is ready for new instructions */
|
|
|
|
/* LCD_CTRL_PORT |= (1 << LCD_RW) | (1 << LCD_RW); // RS=RW=1 */
|
|
/* LCD_DBUS_DDR = 0; // Set all LCD_DBUS_PORT pins as inputs */
|
|
/* clkLCD(); */
|
|
|
|
/* char c = LCD_DBUS_PIN; */
|
|
/* LCD_DBUS_DDR = 0xff; // Reset all LCD_DBUS_PORT pins to outputs */
|
|
/* return c; */
|
|
/* } */
|
|
|
|
/*
|
|
Set all pins of LCD_DBUS, as well as pins LCD_RS, and LCD_RW as outputs
|
|
*/
|
|
static inline void enableLCDOutput(void) {
|
|
LCD_RS_DDR |= (1 << LCD_RS);
|
|
LCD_RW_DDR |= (1 << LCD_RW);
|
|
LCD_ENABLE_DDR |= (1 << LCD_ENABLE);
|
|
|
|
#if defined (FOUR_BIT_MODE) || defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
|
|
LCD_DBUS7_DDR |= (1 << LCD_DBUS7);
|
|
LCD_DBUS6_DDR |= (1 << LCD_DBUS6);
|
|
LCD_DBUS5_DDR |= (1 << LCD_DBUS5);
|
|
LCD_DBUS4_DDR |= (1 << LCD_DBUS4);
|
|
#ifdef EIGHT_BIT_ARBITRARY_PIN_MODE
|
|
LCD_DBUS3_DDR |= (1 << LCD_DBUS3);
|
|
LCD_DBUS2_DDR |= (1 << LCD_DBUS2);
|
|
LCD_DBUS1_DDR |= (1 << LCD_DBUS1);
|
|
LCD_DBUS0_DDR |= (1 << LCD_DBUS0);
|
|
#endif
|
|
#else
|
|
LCD_DBUS_DDR = 0xff;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
Set all pins of LCD_DBUS as well as LCD_RS, and LCD_RW as inputs (disabling their output)
|
|
*/
|
|
static inline void disableLCDOutput(void) {
|
|
LCD_RS_DDR &= ~(1 << LCD_RS);
|
|
LCD_RW_DDR &= ~(1 << LCD_RW);
|
|
LCD_ENABLE_DDR &= ~(1 << LCD_ENABLE);
|
|
|
|
#if defined (FOUR_BIT_MODE) || defined (EIGHT_BIT_ARBITRARY_PIN_MODE)
|
|
LCD_DBUS7_DDR &= ~(1 << LCD_DBUS7);
|
|
LCD_DBUS6_DDR &= ~(1 << LCD_DBUS6);
|
|
LCD_DBUS5_DDR &= ~(1 << LCD_DBUS5);
|
|
LCD_DBUS4_DDR &= ~(1 << LCD_DBUS4);
|
|
#ifdef EIGHT_BIT_ARBITRARY_PIN_MODE
|
|
LCD_DBUS3_DDR &= ~(1 << LCD_DBUS3);
|
|
LCD_DBUS2_DDR &= ~(1 << LCD_DBUS2);
|
|
LCD_DBUS1_DDR &= ~(1 << LCD_DBUS1);
|
|
LCD_DBUS0_DDR &= ~(1 << LCD_DBUS0);
|
|
#endif
|
|
#else
|
|
LCD_DBUS_DDR = 0;
|
|
#endif
|
|
}
|
|
|
|
static inline void softwareLCDInitPulse(void) {
|
|
enableLCDOutput();
|
|
LCD_RS_PORT &= ~(1 << LCD_RS); // RS=0
|
|
LCD_RW_PORT &= ~(1 << LCD_RW); // RW=0
|
|
|
|
#ifdef FOUR_BIT_MODE
|
|
writeLCDNibble_(CMD_INIT);
|
|
#else
|
|
writeLCDByte_(CMD_INIT);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
Do software initialization as specified by the datasheet
|
|
*/
|
|
void initLCD (void) {
|
|
enableLCDOutput();
|
|
|
|
_delay_us(LCD_INIT_DELAY0); // Wait minimum 15ms as per datasheet
|
|
softwareLCDInitPulse();
|
|
_delay_us(LCD_INIT_DELAY1); // Wait minimum 4.1ms as per datasheet
|
|
softwareLCDInitPulse();
|
|
_delay_us(LCD_INIT_DELAY2); // Wait minimum 100us as per datasheet
|
|
softwareLCDInitPulse();
|
|
|
|
#if defined (FOUR_BIT_MODE)
|
|
// Function Set (4-bit interface; 2 lines with 5x7 dot character font)
|
|
writeLCDNibble_(CMD_INIT_FOUR_BIT);
|
|
writeLCDInstr_(CMD_INIT_FOUR_BIT | (1 << INSTR_FUNC_SET_N));
|
|
#else
|
|
// Function set (8-bit interface; 2 lines with 5x7 dot character font)
|
|
// RS=RW=0, DBUS=b00111000,0x38
|
|
writeLCDInstr_(INSTR_FUNC_SET | (1 << INSTR_FUNC_SET_DL) | (1 << INSTR_FUNC_SET_N));
|
|
#endif
|
|
|
|
/* BF now can be checked */
|
|
|
|
// Set functions of LCD
|
|
writeLCDInstr_(INSTR_DISPLAY); // Display off
|
|
_delay_us(LCD_GENERIC_INSTR_DELAY);
|
|
|
|
// Clear display
|
|
writeLCDInstr_(CMD_CLEAR_DISPLAY);
|
|
_delay_us(LCD_CLEAR_DISPLAY_DELAY);
|
|
|
|
// Increment mode, no shift
|
|
writeLCDInstr_(INSTR_ENTRY_SET | (1 << INSTR_ENTRY_SET_ID));
|
|
_delay_us(LCD_GENERIC_INSTR_DELAY);
|
|
|
|
// Display on, cursor on, blink off
|
|
writeLCDInstr_(INSTR_DISPLAY | (1 << INSTR_DISPLAY_D) | (1 << INSTR_DISPLAY_C));
|
|
_delay_us(LCD_GENERIC_INSTR_DELAY);
|
|
|
|
flashLED(5); // DEBUG
|
|
}
|
|
|
|
/*
|
|
Initialize LCD using the internal reset circuitry.
|
|
|
|
Note: This currently only works with 8 bit modes, but is not recommended. Instead use the
|
|
initLCD function which uses the software initialization method and works for 8-bit
|
|
modes as well the 4-bit mode.
|
|
*/
|
|
void initLCDByInternalReset(void) {
|
|
enableLCDOutput();
|
|
|
|
// Function set (8-bit interface; 2 lines with 5x7 dot character font)
|
|
writeLCDInstr_(INSTR_FUNC_SET | (1 << INSTR_FUNC_SET_DL) | (1 << INSTR_FUNC_SET_N));
|
|
|
|
writeLCDInstr_(0x0F);
|
|
writeLCDInstr_(0x06);
|
|
writeLCDInstr_(CMD_CLEAR_DISPLAY);
|
|
_delay_ms(LCD_CLEAR_DISPLAY_DELAY);
|
|
}
|