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Add my own module: LiquidCrystal_SR_LCD3 as well as README for github.

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1 parent 8e72ab0 commit dbe41159f9dadb0545f35ef019642e5ed91b6cd2 @marcmerlin committed Jan 23, 2012
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  1. +303 −0 LiquidCrystal_SR_LCD3.cpp
  2. +94 −0 LiquidCrystal_SR_LCD3.h
  3. +54 −0 README
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+// ---------------------------------------------------------------------------
+// Originally Created by Francisco Malpartida on 2011/08/20.
+// Copyright 2011 - Under creative commons license 3.0:
+// Attribution-ShareAlike CC BY-SA
+//
+// This software is furnished "as is", without technical support, and with no
+// warranty, express or implied, as to its usefulness for any purpose.
+//
+// 2012/01/21 - Marc MERLIN
+// This library, LiquidCrystal_SR_LCD3, was forked off LiquidCrystal_SR which
+// used a different wiring than the Pebble and Pebblev2 (just released by
+// freetronics in the arduino miniconf as part of linux.conf.au 2012) and
+// therefore this code organizes the output data differently.
+//
+// Upstream source for this module is
+// https://github.com/marcmerlin/NewLiquidCrystal
+//
+// Thread Safe: No
+// Extendable: Yes
+//
+// @file LiquidCrystal_SR_LCD3.h
+// Connects an LCD using 3 pins from the Arduino, via an 8-bit
+// ShiftRegister (SR from now on).
+//
+// @brief
+// This is a port of the ShiftRegLCD library from raron and ported to the
+// LCD library.
+//
+// The functionality provided by this class and its base class is identical
+// to the original functionality of the Arduino LiquidCrystal library and can
+// be used as such.
+//
+// Pinout for this code is used by derivatives of the original LCD3Wire page:
+// http://www.arduino.cc/playground/Code/LCD3wires
+//
+// This includes the LCA (linux.conf.au) Arduino Miniconf Pebble:
+// http://shieldlist.org/luke-weston/pebble
+// https://github.com/lukeweston/Pebble
+//
+// It also includes the Pebble v2:
+// http://www.arduinominiconf.org/index.php/Pebble_V2.0_Instructions
+// http://www.freetronics.com/pages/pebble-v2
+// https://github.com/lukeweston/pebble20/blob/master/README.md
+// https://github.com/lukeweston/pebble20/blob/master/pebble-sch.pdf
+//
+// Shiftregister connection description:
+// MC14094 input: Arduino digital pin 2=Clock, pin 3=Data, pin 4=Strobe
+// MC14094 output: Q8=DB4, Q7=DB5, Q6=DB6, Q5=DB7, Q4=E, Q3=RW, Q2=RS, Q1=None
+// http://www.ee.mut.ac.th/datasheet/MC14094.pdf
+//
+// +--------------------------------------------+
+// | Arduino (ATMega 168 or 328) |
+// | D02 D03 D04 |
+// +----+-------------+-------------+-----------+
+// |4 |5 |6
+// |1 |2 |3
+// +----+-------------+-------------+-----------+
+// | Strobe Data Clock |
+// | MC14094 8-bit shift/latch register |
+// | Q8 Q7 Q6 Q5 Q4 Q3 Q2 Q1 |
+// +----+----+----+----+----+----+----+----+----+
+// |11 |12 |13 |14 |7 |6 |5 |4
+// |11 |12 |13 |14 |6 |5 |4
+// +----+----+----+----+----+----+----+---------+
+// | DB4 DB5 DB6 DB7 E RW RS |
+// | LCD KS0066 |
+// +--------------------------------------------+
+//
+// 3 Pins required from the Arduino for Data, Clock, and Enable/Strobe.
+//
+// This code was inspired from LiquidCrystal_SR from
+// http://code.google.com/p/arduinoshiftreglcd/
+// but was written for implementing LiquidCrystal support for the Pebble
+// and Pebblev2 (see below).
+// The Pebbles's LCD and shift register wiring were inspired from this
+// original page:
+// http://www.arduino.cc/playground/Code/LCD3wires
+//
+// Pebbles and the LCD3Wires design are compatible hardware-wise, but
+// the LCD3Wire code does not work with arduino 1.0 anymore and is generally
+// quite limited in functionality compared to this framework that provides the
+// entire LiquidDisplay functionality.
+// Why not just use the LiquidCrystal_SR pinout?
+// - LCD3Wire was first and therefore have hardware that was designed with
+// incompatible (IMO better if you don't mind 3 wires) pinout.
+// - The pinout used here is same saner (the 4 bits for the LCD are all in one
+// nibble of the shift register, not spread across 2 like in the
+// LiquidCrystal_SR pinout)
+//
+// This code makes sure to properly follow the specifications when talking
+// to the LCD while using minimal delays (it's faster than the LCD3wire and aiko
+// pebble code).
+//
+// @author Marc MERLIN - marc_soft<at>merlins.org.
+// ---------------------------------------------------------------------------
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+
+#if (ARDUINO < 100)
+#include <WProgram.h>
+#else
+#include <Arduino.h>
+#endif
+#include <LiquidCrystal_SR_LCD3.h>
+
+// When the display powers up, it is configured as follows:
+//
+// 1. Display clear
+// 2. Function set:
+// DL = 1; 8-bit interface data
+// N = 0; 1-line display
+// F = 0; 5x8 dot character font
+// 3. Display on/off control:
+// D = 0; Display off
+// C = 0; Cursor off
+// B = 0; Blinking off
+// 4. Entry mode set:
+// I/D = 1; Increment by 1
+// S = 0; No shift
+//
+// Note, however, that resetting the Arduino doesn't reset the LCD, so we
+// can't assume that its in that state when a sketch starts (and the
+// LiquidCrystal constructor is called).
+// A call to begin() will reinitialize the LCD.
+
+// STATIC helper routines
+// ---------------------------------------------------------------------------
+/*!
+ @function
+ @abstract waits for a given time in microseconds (compilation dependent).
+ @discussion Waits for a given time defined in microseconds depending on
+ the FAST_MODE define. If the FAST_MODE is defined the call will return
+ inmediatelly.
+ @param uSec[in] time in microseconds.
+ @result None
+ */
+inline static void waitUsec ( uint16_t uSec )
+{
+#ifndef FAST_MODE
+ delayMicroseconds ( uSec );
+#endif // FAST_MODE
+}
+
+
+// CONSTRUCTORS
+// ---------------------------------------------------------------------------
+// Assuming 1 line 8 pixel high font
+LiquidCrystal_SR_LCD3::LiquidCrystal_SR_LCD3 ( uint8_t srdata, uint8_t srclock,
+ uint8_t strobe )
+{
+ init ( srdata, srclock, strobe, 1, 0 );
+}
+// Set nr. of lines, assume 8 pixel high font
+LiquidCrystal_SR_LCD3::LiquidCrystal_SR_LCD3 ( uint8_t srdata, uint8_t srclock,
+ uint8_t strobe, uint8_t lines )
+{
+ init ( srdata, srclock, strobe, lines, 0 );
+}
+
+// Set nr. of lines and font
+LiquidCrystal_SR_LCD3::LiquidCrystal_SR_LCD3 ( uint8_t srdata, uint8_t srclock,
+ uint8_t strobe, uint8_t lines,
+ uint8_t font )
+{
+ init ( srdata, srclock, strobe, lines, font );
+}
+
+
+// PRIVATE METHODS
+// ---------------------------------------------------------------------------
+
+//
+// init
+void LiquidCrystal_SR_LCD3::init(uint8_t srdata, uint8_t srclock, uint8_t strobe,
+ uint8_t lines, uint8_t font )
+{
+ // Initialise private variables
+ _srdata_pin = srdata;
+ _srclock_pin = srclock;
+ _strobe_pin = strobe;
+
+ // Configure control pins as outputs
+ // ------------------------------------------------------------------------
+ pinMode(_srclock_pin, OUTPUT);
+ pinMode(_srdata_pin, OUTPUT);
+ pinMode(_strobe_pin, OUTPUT);
+
+ // Initialize _strobe_pin at low.
+ digitalWrite( _strobe_pin, LOW );
+ // Little trick to force a pulse of the LCD enable bit and make sure it is
+ // low before we start further writes since this is assumed.
+ write4bits(0);
+
+ _displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x10DOTS;
+}
+
+// PUBLIC METHODS
+// ---------------------------------------------------------------------------
+
+//
+// begin
+void LiquidCrystal_SR_LCD3::begin(uint8_t cols, uint8_t lines, uint8_t dotsize)
+{
+ if (lines > 1)
+ {
+ _displayfunction |= LCD_2LINE;
+ }
+
+ _numlines = lines;
+ _cols = cols;
+
+ // 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 before 4.5V so we'll wait
+ // 50
+ // ---------------------------------------------------------------------------
+ delayMicroseconds(50000);
+
+ // This init is copied verbatim from the spec sheet.
+ // 8 bit codes are shifted to 4 bit
+ write4bits((LCD_FUNCTIONSET | LCD_8BITMODE) >> 4);
+ delayMicroseconds(4500); // wait more than 4.1ms
+
+ // Second try
+ write4bits((LCD_FUNCTIONSET | LCD_8BITMODE) >> 4);
+ delayMicroseconds(150);
+ // Third go
+ write4bits((LCD_FUNCTIONSET | LCD_8BITMODE) >> 4);
+
+ // And finally, set to 4-bit interface
+ write4bits((LCD_FUNCTIONSET | LCD_4BITMODE) >> 4);
+
+ // 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);
+ home();
+
+}
+
+/************ low level data pushing commands **********/
+
+// Code below was borrowed from LCD3Wire from
+// http://www.arduino.cc/playground/Code/LCD3wires
+
+// bitmasks for control bits on shift register
+#define SR_EN_BIT B00010000 // LCD Data enable bit.
+#define SR_RW_BIT B00100000 // RW can be pinned low since we only send
+#define SR_RS_BIT B01000000 // LOW: command. HIGH: character.
+
+void LiquidCrystal_SR_LCD3::send(uint8_t value, uint8_t mode)
+{
+ uint8_t nibble;
+
+ mode = mode ? SR_RS_BIT : 0; // RS bit; LOW: command. HIGH: character.
+
+ nibble = value >> 4; // Get high nibble.
+ write4bits(nibble | mode);
+
+ //delay(1); // This was in the LCD3 code but does not seem needed -- merlin
+
+ nibble = value & 15; // Get low nibble
+ write4bits(nibble | mode);
+}
+
+void LiquidCrystal_SR_LCD3::write4bits(uint8_t nibble)
+{
+ nibble &= ~SR_RW_BIT; // set RW LOW (we do this always since we only write).
+
+ // Send a High transition to display the data that was pushed
+ nibble |= SR_EN_BIT; // LCD Data Enable HIGH
+ _pushOut(nibble);
+ nibble &= ~SR_EN_BIT; // LCD Data Enable LOW
+ _pushOut(nibble);
+}
+
+// push byte to shift register and on to LCD
+void LiquidCrystal_SR_LCD3::_pushOut(uint8_t nibble)
+{
+ // Make data available for pushing to the LCD.
+ shiftOut(_srdata_pin, _srclock_pin, LSBFIRST, nibble);
+
+ // Make new data active.
+ digitalWrite(_strobe_pin, HIGH);
+ waitUsec( 1 ); // strobe pulse must be >450ns (old code had 10ms)
+ digitalWrite(_strobe_pin, LOW);
+ waitUsec( 40 ); // commands need > 37us to settle
+}
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+// ---------------------------------------------------------------------------
+// Created by Francisco Malpartida on 20/08/11.
+// Copyright 2011 - Under creative commons license 3.0:
+// Attribution-ShareAlike CC BY-SA
+//
+// This module is by Marc MERLIN <marc_soft<at>merlins.org>
+// See .cpp file for hardware details.
+// ---------------------------------------------------------------------------
+#ifndef _LIQUIDCRYSTAL_SR_LCD3_
+#define _LIQUIDCRYSTAL_SR_LCD3_
+
+#include <inttypes.h>
+#include <LCD.h>
+
+
+class LiquidCrystal_SR_LCD3 : public LCD
+{
+public:
+ /*!
+ @method
+ @abstract LCD SHIFT REGISTER constructors.
+ @discussion Defines the pin assignment that the LCD will have.
+ The constructor does not initialize the LCD. Assuming 1 line 8 pixel high
+ font.
+
+ @param srdata[in] pin for shiftregister data line.
+ @param srclock[in] pin for shiftregister clock line.
+ @param enable[in] enable pin for the shiftregister (also called strobe).
+ */
+ LiquidCrystal_SR_LCD3 ( uint8_t srdata, uint8_t srclock, uint8_t enable );
+
+
+ // Set nr. of lines, assume 8 pixel high font
+ LiquidCrystal_SR_LCD3 ( uint8_t srdata, uint8_t srclock, uint8_t enable,
+ uint8_t lines );
+
+ // Set nr. of lines and font
+ LiquidCrystal_SR_LCD3( uint8_t srdata, uint8_t srclock, uint8_t enable,
+ uint8_t lines, uint8_t font );
+
+
+ /*!
+ @function
+ @abstract LCD initialization.
+ @discussion Initializes the LCD to a given size (col, row). This methods
+ initializes the LCD, therefore, it MUST be called prior to using any other
+ method from this class or parent class.
+
+ @param cols[in] the number of columns that the display has
+ @param rows[in] the number of rows that the display has
+ @param charsize[in] size of the characters of the LCD: LCD_5x8DOTS or
+ LCD_5x10DOTS.
+ */
+ virtual void begin(uint8_t cols, uint8_t rows, uint8_t charsize = LCD_5x8DOTS);
+
+ /*!
+ @function
+ @abstract Send a particular value to the LCD.
+ @discussion Sends a particular value to the LCD for writing to the LCD or
+ as an LCD command using the shift register.
+
+ Users should never call this method.
+
+ @param value[in] Value to send to the LCD.
+ @result mode LOW - write to the LCD CGRAM, HIGH - write a command to
+ the LCD.
+ */
+ virtual void send(uint8_t value, uint8_t mode);
+
+
+private:
+
+ /*!
+ @method
+ @abstract Initializes the LCD pin allocation
+ @discussion Initializes the LCD pin allocation and configuration.
+ */
+ void init ( uint8_t srdata, uint8_t srclock, uint8_t enable, uint8_t lines,
+ uint8_t font );
+ /*!
+ @method
+ @abstract For sending data when initializing the display to 4-bit
+ @discussion Initializes the LCD pin allocation and configuration.
+ */
+ void write4bits ( uint8_t );
+ void _pushOut ( uint8_t );
+
+ uint8_t _srdata_pin; // Serial Data pin
+ uint8_t _srclock_pin; // Clock Pin
+ uint8_t _strobe_pin; // Enable Pin
+};
+
+#endif
+
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