open-access-control-minimal.../libraries/ShiftLCD/ShiftLCD.cpp

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#include "ShiftLCD.h"
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
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#include "Arduino.h"
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/**
* This is a modified version of the standard LiquidCrystal class that
* ships with the Arduino software.
*
* It has been modified to work with either one or two eight bit shift registers
* in 4 and 8 bit mode respectivly
*
* The original file was released under the LGPL licence which I have to confess
* I found more than a little confusing. I belive that I am obligated to release
* this software under the GPL licence, as it is a derivitive work:
* (if not, I am very sorry and please tell me what I should hve done)
*
*******************************************************************************
ShiftLCD, allows the HD44780 LCD to be opertaed via a shift register
Copyright (C) 2010 Chris Parish
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/>.
*******************************************************************************
* Please see the example files for usage information
*/
ShiftLCD::ShiftLCD(uint8_t dp, uint8_t cp, uint8_t lp, uint8_t mode)
{
init (dp, cp, lp, mode);
}
void ShiftLCD::init(uint8_t dp, uint8_t cp, uint8_t lp, uint8_t mode)
{
_data_pin = dp;
_clock_pin = cp;
_latch_pin = lp;
_backlight = LCD_BL_PIN;
pinMode(_data_pin, OUTPUT);
pinMode(_clock_pin, OUTPUT);
pinMode(_latch_pin, OUTPUT);
if (mode <= 4)
_displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
else
_displayfunction = LCD_8BITMODE | LCD_1LINE | LCD_5x8DOTS;
begin(16, 1);
}
void ShiftLCD::begin(uint8_t cols, uint8_t lines, uint8_t dotsize) {
if (lines > 1) {
_displayfunction |= LCD_2LINE;
}
_numlines = lines;
_currline = 0;
// for some 1 line displays you can select a 10 pixel high font
if ((dotsize != 0) && (lines == 1)) {
_displayfunction |= LCD_5x10DOTS;
}
// SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
// according to datasheet, we need at least 40ms after power rises above 2.7V
// before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
delayMicroseconds(50000);
// clear the shift register by sending 16 0's to it
shiftOut(_data_pin, _clock_pin, LSBFIRST, B00000000);
shiftOut(_data_pin, _clock_pin, LSBFIRST, B00000000);
//put the LCD into 4 bit or 8 bit mode
if (! (_displayfunction & LCD_8BITMODE)) {
// this is according to the hitachi HD44780 datasheet
// figure 24, pg 46
// we start in 8bit mode, try to set 4 bit mode
write4bits(0x03, LOW);
delayMicroseconds(4500); // wait min 4.1ms
// second try
write4bits(0x03, LOW);
delayMicroseconds(4500); // wait min 4.1ms
// third go!
write4bits(0x03, LOW);
delayMicroseconds(150);
// finally, set to 8-bit interface
write4bits(0x02, LOW);
} else {
// this is according to the hitachi HD44780 datasheet
// page 45 figure 23
// Send function set command sequence
command(LCD_FUNCTIONSET | _displayfunction);
delayMicroseconds(4500); // wait more than 4.1ms
// second try
command(LCD_FUNCTIONSET | _displayfunction);
delayMicroseconds(150);
// third go
command(LCD_FUNCTIONSET | _displayfunction);
}
// finally, set # lines, font size, etc.
command(LCD_FUNCTIONSET | _displayfunction);
// turn the display on with no cursor or blinking default
_displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
display();
// clear it off
clear();
// Initialize to default text direction (for romance languages)
_displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
// set the entry mode
command(LCD_ENTRYMODESET | _displaymode);
}
/********** high level commands, for the user! */
void ShiftLCD::clear()
{
command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero
delayMicroseconds(2000); // this command takes a long time!
}
void ShiftLCD::home()
{
command(LCD_RETURNHOME); // set cursor position to zero
delayMicroseconds(2000); // this command takes a long time!
}
void ShiftLCD::setCursor(uint8_t col, uint8_t row)
{
int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
if ( row > _numlines ) {
row = _numlines-1; // we count rows starting w/0
}
command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
}
// Turn the display on/off (quickly)
void ShiftLCD::noDisplay() {
_displaycontrol &= ~LCD_DISPLAYON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void ShiftLCD::display() {
_displaycontrol |= LCD_DISPLAYON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// Turns the underline cursor on/off
void ShiftLCD::noCursor() {
_displaycontrol &= ~LCD_CURSORON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void ShiftLCD::cursor() {
_displaycontrol |= LCD_CURSORON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// Turn on and off the blinking cursor
void ShiftLCD::noBlink() {
_displaycontrol &= ~LCD_BLINKON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
void ShiftLCD::blink() {
_displaycontrol |= LCD_BLINKON;
command(LCD_DISPLAYCONTROL | _displaycontrol);
}
// These commands scroll the display without changing the RAM
void ShiftLCD::scrollDisplayLeft(void) {
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
}
void ShiftLCD::scrollDisplayRight(void) {
command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
}
// This is for text that flows Left to Right
void ShiftLCD::leftToRight(void) {
_displaymode |= LCD_ENTRYLEFT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This is for text that flows Right to Left
void ShiftLCD::rightToLeft(void) {
_displaymode &= ~LCD_ENTRYLEFT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This will 'right justify' text from the cursor
void ShiftLCD::autoscroll(void) {
_displaymode |= LCD_ENTRYSHIFTINCREMENT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This will 'left justify' text from the cursor
void ShiftLCD::noAutoscroll(void) {
_displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
command(LCD_ENTRYMODESET | _displaymode);
}
// This will turn the backlight on
void ShiftLCD::backlightOn(void) {
_backlight = LCD_BL_PIN;
updateBacklight();
}
// This will turn the backlight off
void ShiftLCD::backlightOff(void) {
_backlight &= ~LCD_BL_PIN;
updateBacklight();
}
// Allows us to fill the first 8 CGRAM locations
// with custom characters
void ShiftLCD::createChar(uint8_t location, uint8_t charmap[]) {
location &= 0x7; // we only have 8 locations 0-7
command(LCD_SETCGRAMADDR | (location << 3));
for (int i=0; i<8; i++) {
write(charmap[i]);
}
}
/*********** mid level commands, for sending data/cmds */
inline void ShiftLCD::command(uint8_t value) {
send(value, false);
}
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inline size_t ShiftLCD::write(uint8_t value) {
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send(value, true);
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return 1;
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}
/************ low level data pushing commands **********/
void ShiftLCD::updateBacklight(void) {
if (_displayfunction & LCD_8BITMODE) {
digitalWrite(_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, _backlight);
shiftOut(_data_pin, _clock_pin, LSBFIRST, B00000000);
digitalWrite(_latch_pin, LOW);
} else {
digitalWrite(_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, _backlight);
digitalWrite(_latch_pin, LOW);
}
}
// write either command or data, with automatic 4/8-bit selection
void ShiftLCD::send(uint8_t value, uint8_t mode) {
if (_displayfunction & LCD_8BITMODE) {
write8bits(value, mode);
} else {
write4bits(value>>4, mode);
write4bits(value, mode);
}
}
void ShiftLCD::write4bits(uint8_t value, uint8_t mode) {
int EN_SWITCH = B00000010;
int RS_SWITCH = B00000001;
int cmd = 0;
int data = 0;
if (!mode) {
cmd = 0 | _backlight;
} else {
cmd = LCD_RS_PIN | _backlight;
}
data = value<<4 & B11110000;
cmd |= EN_SWITCH;
digitalWrite(_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, data | cmd);
digitalWrite(_latch_pin, LOW);
delayMicroseconds(1);
cmd &= ~EN_SWITCH;
digitalWrite(_latch_pin, HIGH);
shiftOut (_data_pin, _clock_pin, LSBFIRST, data | cmd);
digitalWrite(_latch_pin, LOW);
delayMicroseconds(1);
cmd |= EN_SWITCH;
digitalWrite(_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, data | cmd);
digitalWrite(_latch_pin, LOW);
delayMicroseconds(100);
}
void ShiftLCD::write8bits(uint8_t value, uint8_t mode) {
int EN_SWITCH = B00000010;
int RS_SWITCH = B00000001;
int cmd = 0;
if (!mode) {
cmd = 0;
} else {
cmd = RS_SWITCH;
}
//set enable low
cmd |= EN_SWITCH;
digitalWrite (_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, cmd);
shiftOut(_data_pin, _clock_pin, LSBFIRST, value);
digitalWrite (_latch_pin, LOW);
//delay (500);
//set enable high;
cmd &= ~EN_SWITCH;
digitalWrite (_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, cmd);
shiftOut(_data_pin, _clock_pin, LSBFIRST, value);
digitalWrite (_latch_pin, LOW);
delayMicroseconds (1);
//delay (500);
//set enable low
cmd |= EN_SWITCH;
digitalWrite (_latch_pin, HIGH);
shiftOut(_data_pin, _clock_pin, LSBFIRST, cmd);
shiftOut(_data_pin, _clock_pin, LSBFIRST, value);
digitalWrite (_latch_pin, LOW);
delayMicroseconds (100);
}