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;
};