![]() | LCD Library 1.2.1 LCD Library - LCD control class hierarchy library. Drop in replacement for the LiquidCrystal Library. |
00001 // ---------------------------------------------------------------------------00002 // Created by Francisco Malpartida on 20/08/11.00003 // Copyright 2011 - Under creative commons license 3.0:00004 // Attribution-ShareAlike CC BY-SA00005 //00006 // This software is furnished "as is", without technical support, and with no 00007 // warranty, express or implied, as to its usefulness for any purpose.00008 //00009 // Thread Safe: No00010 // Extendable: Yes00011 //00012 // @file LiquidCrystal_SR.h00013 // Connects an LCD using 2 or 3 pins from the Arduino, via an 8-bit 00014 // ShiftRegister (SR from now on).00015 // 00016 // @brief 00017 // This is a port of the ShiftRegLCD library from raron and ported to the00018 // LCD library.00019 //00020 // The functionality provided by this class and its base class is identical00021 // to the original functionality of the Arduino LiquidCrystal library and can00022 // be used as such.00023 //00024 // Modified to work serially with the shiftOut() function, an 8-bit00025 // unlatched, no-tristate, unidirectional SIPO (Serial-In-Parallel-Out)00026 // shift register (IE a very simple SR), and an LCD in 4-bit mode.00027 // Any such shift register should do (pref. 74LS family IC's for 2-wire).00028 // I used 74LS164, for the reason that's what I had at hand.00029 //00030 // Connection description:00031 //00032 // SR output:00033 // Bit #0 - N/C - not connected, used to hold a zero00034 // Bit #1 - N/C00035 // Bit #2 - connects to RS (Register Select) on the LCD00036 // Bits #3-6 - connects to LCD data inputs D4 - D7.00037 // Bit #7 - enables the LCD enable-puls (via the diode-resistor AND "gate")00038 //00039 // 2 or 3 Pins required from the Arduino for Data, Clock and (optional) Enable00040 // If not using Enable, the Data pin is used for the enable signal by defining00041 // the same pin for Enable as for Data. Data and Clock outputs/pins goes to00042 // the shiftregister.00043 // LCD RW-pin hardwired to LOW (only writing to LCD).00044 // Busy Flag (BF, data bit D7) is not read.00045 //00046 // Original project homepage: http://code.google.com/p/arduinoshiftreglcd/00047 //00048 //00049 // History00050 // 2012.03.29 bperrybap - Added delays for faster fio shiftout (it got too fast)00051 // AVR needed delay. cmd/write delays are based on CPU speed so it works on pic32.00052 // Added code to support indicating two wire mode by using enable=data pin00053 // (documentation indicated this as working)00054 // Fixed incorrect use of 5x10 for default font - now matches original LQ library.00055 // can now eliminate enable pin in constructor for two wire mode.00056 // 2012.01.16 Florian Fida - faster digitalWrite/shiftOut00057 // 2011.10.29 fmalpartida - adaption of the library to the LCD class hierarchy.00058 // 2011.07.02 Fixed a minor flaw in setCursor function. No functional change, 00059 // just a bit more memory efficient.00060 // Thanks to CapnBry (from google code and github) who noticed it.00061 // URL to his version of shiftregLCD:00062 // https://github.com/CapnBry/HeaterMeter/commit/c6beba1b46b092ab0b33bcbd0a30a201fd1f28c100063 // 2009.07.30 raron - minor corrections to the comments.00064 // Fixed timing to datasheet safe. Fixed keyword highlights.00065 // 2009.07.28 Mircho / raron - a new modification to the schematics, and a00066 // more streamlined interface00067 // 2009.07.27 Thanks to an excellent suggestion from mircho at the Arduino00068 // playgrond forum, the number of wires now required is only two!00069 // 2009.07.25 raron - Fixed comments. I really messed up the comments before 00070 // posting this, so I had to fix it.00071 // Renamed a function, but no improvements or functional changes.00072 // 2009.07.23 Incorporated some proper initialization routines00073 // inspired (lets say copy-paste-tweaked) from LiquidCrystal00074 // library improvements from LadyAda.00075 // 2009.05.23 raron - first version, but based mostly (as in almost verbatim)00076 // on the "official" LiquidCrystal library.00077 //00078 //00079 // @author F. Malpartida - fmalpartida@gmail.com00080 // ---------------------------------------------------------------------------00081 #include <stdio.h>00082 #include <string.h>00083 #include <inttypes.h>00084 00085 #if (ARDUINO < 100)00086 #include <WProgram.h>00087 #else00088 #include <Arduino.h>00089 #endif00090 #include "LiquidCrystal_SR.h"00091 00092 #include "FastIO.h"00093 00094 00095 // CONSTRUCTORS00096 // ---------------------------------------------------------------------------00097 // Assuming 1 line 8 pixel high font00098LiquidCrystal_SR::LiquidCrystal_SR (uint8_t srdata, uint8_t srclock, 00099 uint8_t enable ) 00100 { 00101 init ( srdata, srclock, enable, 1, 0 ); 00102 } 00103 00104 00105 // PRIVATE METHODS00106 // ---------------------------------------------------------------------------00107 00108 //00109 // init00110 void LiquidCrystal_SR::init(uint8_t srdata, uint8_t srclock, uint8_t enable, 00111 uint8_t lines, uint8_t font) 00112 { 00113 // Initialise private variables00114 _two_wire = 0; 00115 00116 _srDataRegister = fio_pinToOutputRegister(srdata); 00117 _srDataBit = fio_pinToBit(srdata); 00118 _srClockRegister = fio_pinToOutputRegister(srclock); 00119 _srClockBit = fio_pinToBit(srclock); 00120 00121 if ((enable == TWO_WIRE) || (enable == srdata)) 00122 { 00123 _two_wire = 1; 00124 _srEnableRegister = _srDataRegister; 00125 _srEnableBit = _srDataBit; 00126 } 00127 else00128 { 00129 _srEnableRegister = fio_pinToOutputRegister(enable); 00130 _srEnableBit = fio_pinToBit(enable); 00131 } 00132 00133 // Configure control pins as outputs00134 // ------------------------------------------------------------------------00135 00136 _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS; 00137 } 00138 00139 //00140 // shiftIt00141 void LiquidCrystal_SR::shiftIt(uint8_t val) 00142 { 00143 if (_two_wire) 00144 { 00145 // Clear to get Enable LOW00146 fio_shiftOut(_srDataRegister, _srDataBit, _srClockRegister, _srClockBit); 00147 } 00148 fio_shiftOut(_srDataRegister, _srDataBit, _srClockRegister, _srClockBit, val, MSBFIRST); 00149 00150 // LCD ENABLE PULSE00151 //00152 // While this library is written with a shift register without an output00153 // latch in mind, it can work in 3-wire mode with a shiftregister with a00154 // latch. The shiftregister latch pin (STR, RCL or similar) is then00155 // connected to the LCD enable pin. The LCD is (very likely) slower00156 // to read the Enable pulse, and then reads the new contents of the SR.00157 ATOMIC_BLOCK(ATOMIC_RESTORESTATE) 00158 { 00159 fio_digitalWrite_HIGH(_srEnableRegister, _srEnableBit); 00160 waitUsec (1); // enable pulse must be >450ns 00161 fio_digitalWrite_SWITCHTO(_srEnableRegister, _srEnableBit, LOW); 00162 } // end critical section00163 } 00164 00165 // PUBLIC METHODS00166 // ---------------------------------------------------------------------------00167 00168 00169 /************ low level data pushing commands **********/00170 //00171 // send00172voidLiquidCrystal_SR::send(uint8_t value, uint8_t mode) 00173 { 00174 // Divide byte in two nibbles include the RS signal00175 // and format it for shiftregister output wiring to the LCD00176 // We are only interested in my COMMAND or DATA for myMode00177 uint8_t myMode = ( mode == DATA ) ? SR_RS_BIT : 0; // RS bit; LOW: command. HIGH: character.00178 00179 if ( mode != FOUR_BITS ) 00180 { 00181 shiftIt(myMode | SR_EN_BIT | ((value >> 1) & 0x78)); // upper nibble00182 } 00183 00184 shiftIt(myMode | SR_EN_BIT | ((value << 3) & 0x78)); // lower nibble00185 /*00186 * Add some delay since this code is so fast it needs some added delay00187 * even on AVRs because the shiftout is shorter than the LCD command execution time.00188 */00189 #if (F_CPU <= 16000000)00190 if(_two_wire) 00191 delayMicroseconds ( 10 ); 00192 else00193 delayMicroseconds ( 17 ); // 3 wire mode is faster so it must delay longer00194 #else00195 delayMicroseconds ( 37 ); // commands & data writes need > 37us to complete00196 #endif00197 00198 } 00199 00200 //00201 // setBacklightPin00202voidLiquidCrystal_SR::setBacklightPin ( uint8_t pin, t_backlighPol pol ) 00203 { } 00204 00205 //00206 // setBacklight00207voidLiquidCrystal_SR::setBacklight ( uint8_t mode ) 00208 { } 00209