LCD Library 1.2.1
LCD Library - LCD control class hierarchy library. Drop in replacement for the LiquidCrystal Library.
/Users/fmalpartida/development/ardWorkspace/LiquidCrystal_I2C/LiquiCrystal_I2C/LiquidCrystal_SR3W.h
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00001 // ---------------------------------------------------------------------------
00002 // Created by Francisco Malpartida on 7.3.2012.
00003 // Copyright 2011 - Under creative commons license 3.0:
00004 //        Attribution-ShareAlike CC BY-SA
00005 //
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: No
00010 // Extendable: Yes
00011 //
00012 // @file LiquidCrystal_SR3W.h
00013 // This file implements a basic liquid crystal library that comes as standard
00014 // in the Arduino SDK but using a generic SHIFT REGISTER extension board.
00015 // 
00016 // @brief 
00017 // This is a basic implementation of the LiquidCrystal library of the
00018 // Arduino SDK. The original library has been reworked in such a way that 
00019 // this class implements the all methods to command an LCD based
00020 // on the Hitachi HD44780 and compatible chipsets using a 3 wire latching
00021 // shift register. While it has been tested with a 74HC595N shift register
00022 // it should also work with other latching shift registers such as the MC14094
00023 // and the HEF4094
00024 //
00025 // This particular driver has been created as generic as possible to enable
00026 // users to configure and connect their LCDs using just 3 digital IOs from the
00027 // AVR or Arduino, and connect the LCD to the outputs of the shiftregister
00028 // in any configuration. The library is configured by passing the IO pins
00029 // that control the strobe, data and clock of the shift register and a map
00030 // of how the shiftregister is connected to the LCD.
00031 // 
00032 //
00033 //   +--------------------------------------------+
00034 //   |                 MCU                        |
00035 //   |   IO1           IO2           IO3          |
00036 //   +----+-------------+-------------+-----------+
00037 //        |             |             |
00038 //        |             |             |
00039 //   +----+-------------+-------------+-----------+
00040 //   |    Strobe        Data          Clock       |
00041 //   |          8-bit shift/latch register        | 74HC595N
00042 //   |    Qa0  Qb1  Qc2  Qd3  Qe4  Qf5  Qg6  Qh7  |
00043 //   +----+----+----+----+----+----+----+----+----+
00044 //        |    |    |    |    |    |    |    
00045 //        |11  |12  |13  |14  |6   |5   |4   (LCD pins)
00046 //   +----+----+----+----+----+----+----+----+----+
00047 //   |    DB4  DB5  DB6  DB7  E    Rw   RS        |
00048 //   |                 LCD Module                 |
00049 //
00050 // NOTE: Rw is not used by the driver so it can be connected to GND.
00051 //
00052 // The functionality provided by this class and its base class is identical
00053 // to the original functionality of the Arduino LiquidCrystal library.
00054 //
00055 //
00056 // @author F. Malpartida - fmalpartida@gmail.com
00057 // ---------------------------------------------------------------------------
00058 #ifndef _LIQUIDCRYSTAL_SR3W_H_
00059 #define _LIQUIDCRYSTAL_SR3W_H_
00060 
00061 #include <inttypes.h>
00062 #include "LCD.h"
00063 #include "FastIO.h"
00064 
00065 
00066 class LiquidCrystal_SR3W : public LCD 
00067 {
00068 public:
00069    
00090    LiquidCrystal_SR3W(uint8_t data, uint8_t clk, uint8_t strobe);
00091    // Constructor with backlight control
00092    LiquidCrystal_SR3W(uint8_t data, uint8_t clk, uint8_t strobe, 
00093                       uint8_t backlighPin, t_backlighPol pol);   
00094    
00112    LiquidCrystal_SR3W(uint8_t data, uint8_t clk, uint8_t strobe, 
00113                       uint8_t En, uint8_t Rw, uint8_t Rs, 
00114                       uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7 );
00115    // Constructor with backlight control
00116    LiquidCrystal_SR3W( uint8_t data, uint8_t clk, uint8_t strobe,
00117                       uint8_t En, uint8_t Rw, uint8_t Rs, 
00118                       uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7,
00119                       uint8_t backlighPin, t_backlighPol pol);
00120    
00133    virtual void send(uint8_t value, uint8_t mode);
00134    
00143    void setBacklightPin ( uint8_t value, t_backlighPol pol );
00144    
00154    void setBacklight ( uint8_t value );
00155    
00156 private:
00157    
00163    int  init(uint8_t data, uint8_t clk, uint8_t strobe, 
00164              uint8_t Rs, uint8_t Rw, uint8_t En,
00165              uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
00166    
00175    void write4bits(uint8_t value, uint8_t mode);
00176    
00183    void loadSR(uint8_t value);
00184    
00185    
00186    fio_bit      _strobe;           // shift register strobe pin
00187    fio_register _strobe_reg;       // SR strobe pin MCU register
00188    fio_bit      _data;             // shift register data pin
00189    fio_register _data_reg;         // SR data pin MCU register
00190    fio_bit      _clk;              // shift register clock pin
00191    fio_register _clk_reg;          // SR clock pin MCU register
00192    uint8_t      _En;               // LCD expander word for enable pin
00193    uint8_t      _Rw;               // LCD expander word for R/W pin
00194    uint8_t      _Rs;               // LCD expander word for Register Select pin
00195    uint8_t      _data_pins[4];     // LCD data lines
00196    uint8_t      _backlightPinMask; // Backlight IO pin mask
00197    uint8_t      _backlightStsMask; // Backlight status mask
00198    
00199 };
00200 
00201 #endif
00202 
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