PololuHD44780.h

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// Copyright Pololu Corporation.  For more information, see http://www.pololu.com/
 
#pragma once
#include <Arduino.h>
#include <util/delay.h>
 
class PololuHD44780Base : public Print
{
public:
 
    PololuHD44780Base();
 
    virtual void initPins() = 0;
 
    void init()
    {
        if (!initialized)
        {
            initialized = true;
            init2();
        }
    }
 
    void reinitialize()
    {
        initialized = true;
        init2();
    }
 
    virtual void send(uint8_t data, bool rsValue, bool only4bits) = 0;
 
private:
 
    void sendAndDelay(uint8_t data, bool rsValue, bool only4bit);
 
    void sendCommand(uint8_t cmd)
    {
        sendAndDelay(cmd, false, false);
    }
 
    void sendCommand4Bit(uint8_t cmd)
    {
        sendAndDelay(cmd, false, true);
    }
 
    void sendData(uint8_t data)
    {
        sendAndDelay(data, true, false);
    }
 
public:
 
    void clear();
 
    void loadCustomCharacter(const uint8_t * picture, uint8_t number);
 
    void loadCustomCharacterFromRam(const uint8_t * picture, uint8_t number);
 
    void loadCustomCharacter(const char * picture, uint8_t number)
    {
        loadCustomCharacter((const uint8_t *)picture, number);
    }
 
    void createChar(uint8_t number, uint8_t picture[])
    {
        loadCustomCharacterFromRam(picture, number);
    }
 
    void gotoXY(uint8_t x, uint8_t y);
 
    void setCursor(uint8_t col, uint8_t row)
    {
        gotoXY(col, row);
    }
 
    void noDisplay();
 
    void display();
 
    void noCursor();
 
    void cursor();
 
    void noBlink();
 
    void blink();
 
    void cursorSolid();
 
    void cursorBlinking();
 
    void hideCursor();
 
    void scrollDisplayLeft();
 
    void scrollDisplayRight();
 
    void home();
 
    void leftToRight();
 
    void rightToLeft();
 
    void autoscroll();
 
    void noAutoscroll();
 
    //void initPrintf();
    //void initPrintf(uint8_t lcdWidth, uint8_t lcdHeight);
 
    void command(uint8_t cmd)
    {
        sendCommand(cmd);
    }
 
    virtual size_t write(uint8_t c);
 
    virtual size_t write(const uint8_t * buffer, size_t size);
 
    // This allows us to easily call overrides of write that are
    // defined in Print.
    using Print::write;
 
private:
    bool initialized;
 
    /* The lower three bits of this store the arguments to the
     * last "Display on/off control" HD44780 command that we sent.
     * bit 2: D: Whether the display is on.
     * bit 1: C: Whether the cursor is shown.
     * bit 0: B: Whether the cursor is blinking. */
    uint8_t displayControl;
 
    /* The lower two bits of this variable store the arguments to the
     * last "Entry mode set" HD44780 command that we sent.
     * bit 1: I/D: 0 for moving the cursor to the left after data is written,
     *        1 for moving the cursor to the right.
     * bit 0: 1 for autoscrolling. */
    uint8_t entryMode;
 
    void setEntryMode(uint8_t entryMode);
    void setDisplayControl(uint8_t displayControl);
 
    void init2();
};
 
class PololuHD44780 : public PololuHD44780Base
{
public:
    PololuHD44780(uint8_t rs, uint8_t e, uint8_t db4, uint8_t db5,
        uint8_t db6, uint8_t db7)
    {
        this->rs = rs;
        this->e = e;
        this->db4 = db4;
        this->db5 = db5;
        this->db6 = db6;
        this->db7 = db7;
    }
 
    virtual void initPins()
    {
        digitalWrite(e, LOW);
        pinMode(e, OUTPUT);
    }
 
    virtual void send(uint8_t data, bool rsValue, bool only4bits)
    {
        digitalWrite(rs, rsValue);
 
        pinMode(rs, OUTPUT);
        pinMode(db4, OUTPUT);
        pinMode(db5, OUTPUT);
        pinMode(db6, OUTPUT);
        pinMode(db7, OUTPUT);
 
        if (!only4bits) { sendNibble(data >> 4); }
        sendNibble(data & 0x0F);
    }
 
private:
 
    void sendNibble(uint8_t data)
    {
        digitalWrite(db4, data >> 0 & 1);
        digitalWrite(db5, data >> 1 & 1);
        digitalWrite(db6, data >> 2 & 1);
        digitalWrite(db7, data >> 3 & 1);
 
        digitalWrite(e, HIGH);
        _delay_us(1);  // Must be at least 450 ns.
        digitalWrite(e, LOW);
        _delay_us(1);  // Must be at least 550 ns.
    }
 
    uint8_t rs, e, db4, db5, db6, db7;
};