initial cleanup and mapping
This commit is contained in:
unknown
495
devLib/lcd.c
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495
devLib/lcd.c
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/*
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* lcd.c:
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* Text-based LCD driver.
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* This is designed to drive the parallel interface LCD drivers
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* based in the Hitachi HD44780U controller and compatables.
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*
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* Copyright (c) 2012 Gordon Henderson.
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***********************************************************************
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* This file is part of wiringPi:
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* https://projects.drogon.net/raspberry-pi/wiringpi/
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*
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* wiringPi is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* wiringPi is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
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***********************************************************************
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <wiringPi.h>
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#include "lcd.h"
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#ifndef TRUE
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# define TRUE (1==1)
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# define FALSE (1==2)
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#endif
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// HD44780U Commands
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#define LCD_CLEAR 0x01
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#define LCD_HOME 0x02
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#define LCD_ENTRY 0x04
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#define LCD_CTRL 0x08
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#define LCD_CDSHIFT 0x10
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#define LCD_FUNC 0x20
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#define LCD_CGRAM 0x40
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#define LCD_DGRAM 0x80
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// Bits in the entry register
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#define LCD_ENTRY_SH 0x01
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#define LCD_ENTRY_ID 0x02
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// Bits in the control register
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#define LCD_BLINK_CTRL 0x01
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#define LCD_CURSOR_CTRL 0x02
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#define LCD_DISPLAY_CTRL 0x04
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// Bits in the function register
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#define LCD_FUNC_F 0x04
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#define LCD_FUNC_N 0x08
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#define LCD_FUNC_DL 0x10
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#define LCD_CDSHIFT_RL 0x04
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struct lcdDataStruct
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{
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int bits, rows, cols ;
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int rsPin, strbPin ;
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int dataPins [8] ;
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int cx, cy ;
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} ;
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struct lcdDataStruct *lcds [MAX_LCDS] ;
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static int lcdControl ;
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// Row offsets
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static const int rowOff [4] = { 0x00, 0x40, 0x14, 0x54 } ;
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/*
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* strobe:
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* Toggle the strobe (Really the "E") pin to the device.
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* According to the docs, data is latched on the falling edge.
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*********************************************************************************
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*/
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static void strobe (const struct lcdDataStruct *lcd)
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{
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// Note timing changes for new version of delayMicroseconds ()
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digitalWrite (lcd->strbPin, 1) ; delayMicroseconds (50) ;
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digitalWrite (lcd->strbPin, 0) ; delayMicroseconds (50) ;
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}
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/*
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* sentDataCmd:
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* Send an data or command byte to the display.
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*********************************************************************************
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*/
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static void sendDataCmd (const struct lcdDataStruct *lcd, unsigned char data)
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{
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register unsigned char myData = data ;
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unsigned char i, d4 ;
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if (lcd->bits == 4)
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{
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d4 = (myData >> 4) & 0x0F;
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for (i = 0 ; i < 4 ; ++i)
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{
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digitalWrite (lcd->dataPins [i], (d4 & 1)) ;
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d4 >>= 1 ;
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}
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strobe (lcd) ;
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d4 = myData & 0x0F ;
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for (i = 0 ; i < 4 ; ++i)
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{
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digitalWrite (lcd->dataPins [i], (d4 & 1)) ;
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d4 >>= 1 ;
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}
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}
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else
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{
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for (i = 0 ; i < 8 ; ++i)
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{
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digitalWrite (lcd->dataPins [i], (myData & 1)) ;
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myData >>= 1 ;
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}
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}
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strobe (lcd) ;
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}
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/*
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* putCommand:
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* Send a command byte to the display
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*********************************************************************************
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*/
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static void putCommand (const struct lcdDataStruct *lcd, unsigned char command)
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{
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digitalWrite (lcd->rsPin, 0) ;
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sendDataCmd (lcd, command) ;
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delay (2) ;
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}
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static void put4Command (const struct lcdDataStruct *lcd, unsigned char command)
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{
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register unsigned char myCommand = command ;
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register unsigned char i ;
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digitalWrite (lcd->rsPin, 0) ;
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for (i = 0 ; i < 4 ; ++i)
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{
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digitalWrite (lcd->dataPins [i], (myCommand & 1)) ;
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myCommand >>= 1 ;
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}
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strobe (lcd) ;
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}
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/*
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*********************************************************************************
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* User Callable code below here
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*********************************************************************************
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*/
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/*
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* lcdHome: lcdClear:
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* Home the cursor or clear the screen.
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*********************************************************************************
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*/
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void lcdHome (const int fd)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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putCommand (lcd, LCD_HOME) ;
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lcd->cx = lcd->cy = 0 ;
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delay (5) ;
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}
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void lcdClear (const int fd)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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putCommand (lcd, LCD_CLEAR) ;
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putCommand (lcd, LCD_HOME) ;
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lcd->cx = lcd->cy = 0 ;
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delay (5) ;
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}
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/*
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* lcdDisplay: lcdCursor: lcdCursorBlink:
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* Turn the display, cursor, cursor blinking on/off
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*********************************************************************************
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*/
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void lcdDisplay (const int fd, int state)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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if (state)
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lcdControl |= LCD_DISPLAY_CTRL ;
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else
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lcdControl &= ~LCD_DISPLAY_CTRL ;
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putCommand (lcd, LCD_CTRL | lcdControl) ;
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}
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void lcdCursor (const int fd, int state)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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if (state)
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lcdControl |= LCD_CURSOR_CTRL ;
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else
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lcdControl &= ~LCD_CURSOR_CTRL ;
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putCommand (lcd, LCD_CTRL | lcdControl) ;
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}
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void lcdCursorBlink (const int fd, int state)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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if (state)
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lcdControl |= LCD_BLINK_CTRL ;
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else
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lcdControl &= ~LCD_BLINK_CTRL ;
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putCommand (lcd, LCD_CTRL | lcdControl) ;
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}
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/*
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* lcdSendCommand:
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* Send any arbitary command to the display
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*********************************************************************************
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*/
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void lcdSendCommand (const int fd, unsigned char command)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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putCommand (lcd, command) ;
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}
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/*
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* lcdPosition:
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* Update the position of the cursor on the display.
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* Ignore invalid locations.
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*********************************************************************************
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*/
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void lcdPosition (const int fd, int x, int y)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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if ((x > lcd->cols) || (x < 0))
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return ;
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if ((y > lcd->rows) || (y < 0))
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return ;
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putCommand (lcd, x + (LCD_DGRAM | rowOff [y])) ;
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lcd->cx = x ;
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lcd->cy = y ;
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}
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/*
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* lcdCharDef:
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* Defines a new character in the CGRAM
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*********************************************************************************
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*/
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void lcdCharDef (const int fd, int index, unsigned char data [8])
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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int i ;
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putCommand (lcd, LCD_CGRAM | ((index & 7) << 3)) ;
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digitalWrite (lcd->rsPin, 1) ;
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for (i = 0 ; i < 8 ; ++i)
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sendDataCmd (lcd, data [i]) ;
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}
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/*
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* lcdPutchar:
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* Send a data byte to be displayed on the display. We implement a very
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* simple terminal here - with line wrapping, but no scrolling. Yet.
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*********************************************************************************
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*/
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void lcdPutchar (const int fd, unsigned char data)
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{
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struct lcdDataStruct *lcd = lcds [fd] ;
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digitalWrite (lcd->rsPin, 1) ;
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sendDataCmd (lcd, data) ;
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if (++lcd->cx == lcd->cols)
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{
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lcd->cx = 0 ;
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if (++lcd->cy == lcd->rows)
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lcd->cy = 0 ;
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putCommand (lcd, lcd->cx + (LCD_DGRAM | rowOff [lcd->cy])) ;
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}
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}
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/*
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* lcdPuts:
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* Send a string to be displayed on the display
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*********************************************************************************
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*/
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void lcdPuts (const int fd, const char *string)
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{
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while (*string)
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lcdPutchar (fd, *string++) ;
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}
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/*
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* lcdPrintf:
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* Printf to an LCD display
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*********************************************************************************
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*/
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void lcdPrintf (const int fd, const char *message, ...)
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{
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va_list argp ;
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char buffer [1024] ;
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va_start (argp, message) ;
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vsnprintf (buffer, 1023, message, argp) ;
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va_end (argp) ;
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lcdPuts (fd, buffer) ;
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}
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/*
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* lcdInit:
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* Take a lot of parameters and initialise the LCD, and return a handle to
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* that LCD, or -1 if any error.
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*********************************************************************************
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*/
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int lcdInit (const int rows, const int cols, const int bits,
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const int rs, const int strb,
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const int d0, const int d1, const int d2, const int d3, const int d4,
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const int d5, const int d6, const int d7)
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{
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static int initialised = 0 ;
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unsigned char func ;
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int i ;
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int lcdFd = -1 ;
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struct lcdDataStruct *lcd ;
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if (initialised == 0)
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{
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initialised = 1 ;
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for (i = 0 ; i < MAX_LCDS ; ++i)
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lcds [i] = NULL ;
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}
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// Simple sanity checks
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if (! ((bits == 4) || (bits == 8)))
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return -1 ;
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if ((rows < 0) || (rows > 20))
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return -1 ;
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if ((cols < 0) || (cols > 20))
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return -1 ;
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// Create a new LCD:
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for (i = 0 ; i < MAX_LCDS ; ++i)
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{
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if (lcds [i] == NULL)
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{
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lcdFd = i ;
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break ;
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}
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}
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if (lcdFd == -1)
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return -1 ;
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lcd = (struct lcdDataStruct *)malloc (sizeof (struct lcdDataStruct)) ;
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if (lcd == NULL)
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return -1 ;
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lcd->rsPin = rs ;
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lcd->strbPin = strb ;
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lcd->bits = 8 ; // For now - we'll set it properly later.
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lcd->rows = rows ;
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lcd->cols = cols ;
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lcd->cx = 0 ;
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lcd->cy = 0 ;
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lcd->dataPins [0] = d0 ;
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lcd->dataPins [1] = d1 ;
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lcd->dataPins [2] = d2 ;
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lcd->dataPins [3] = d3 ;
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lcd->dataPins [4] = d4 ;
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lcd->dataPins [5] = d5 ;
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lcd->dataPins [6] = d6 ;
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lcd->dataPins [7] = d7 ;
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lcds [lcdFd] = lcd ;
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digitalWrite (lcd->rsPin, 0) ; pinMode (lcd->rsPin, OUTPUT) ;
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digitalWrite (lcd->strbPin, 0) ; pinMode (lcd->strbPin, OUTPUT) ;
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for (i = 0 ; i < bits ; ++i)
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{
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digitalWrite (lcd->dataPins [i], 0) ;
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pinMode (lcd->dataPins [i], OUTPUT) ;
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}
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delay (35) ; // mS
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// 4-bit mode?
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// OK. This is a PIG and it's not at all obvious from the documentation I had,
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// so I guess some others have worked through either with better documentation
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// or more trial and error... Anyway here goes:
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//
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// It seems that the controller needs to see the FUNC command at least 3 times
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// consecutively - in 8-bit mode. If you're only using 8-bit mode, then it appears
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// that you can get away with one func-set, however I'd not rely on it...
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//
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// So to set 4-bit mode, you need to send the commands one nibble at a time,
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// the same three times, but send the command to set it into 8-bit mode those
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// three times, then send a final 4th command to set it into 4-bit mode, and only
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// then can you flip the switch for the rest of the library to work in 4-bit
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// mode which sends the commands as 2 x 4-bit values.
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if (bits == 4)
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{
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func = LCD_FUNC | LCD_FUNC_DL ; // Set 8-bit mode 3 times
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put4Command (lcd, func >> 4) ; delay (35) ;
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put4Command (lcd, func >> 4) ; delay (35) ;
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put4Command (lcd, func >> 4) ; delay (35) ;
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func = LCD_FUNC ; // 4th set: 4-bit mode
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put4Command (lcd, func >> 4) ; delay (35) ;
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lcd->bits = 4 ;
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}
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else
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{
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func = LCD_FUNC | LCD_FUNC_DL ;
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putCommand (lcd, func ) ; delay (35) ;
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putCommand (lcd, func ) ; delay (35) ;
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putCommand (lcd, func ) ; delay (35) ;
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}
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if (lcd->rows > 1)
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{
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func |= LCD_FUNC_N ;
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putCommand (lcd, func) ; delay (35) ;
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}
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// Rest of the initialisation sequence
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lcdDisplay (lcdFd, TRUE) ;
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lcdCursor (lcdFd, FALSE) ;
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lcdCursorBlink (lcdFd, FALSE) ;
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lcdClear (lcdFd) ;
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putCommand (lcd, LCD_ENTRY | LCD_ENTRY_ID) ;
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putCommand (lcd, LCD_CDSHIFT | LCD_CDSHIFT_RL) ;
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return lcdFd ;
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}
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