GpioLcdDisplay.java

package com.pi4j.component.lcd.impl;

/*
 * #%L
 * **********************************************************************
 * ORGANIZATION  :  Pi4J
 * PROJECT       :  Pi4J :: Device Abstractions
 * FILENAME      :  GpioLcdDisplay.java  
 * 
 * This file is part of the Pi4J project. More information about 
 * this project can be found here:  http://www.pi4j.com/
 * **********************************************************************
 * %%
 * Copyright (C) 2012 - 2013 Pi4J
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */


import com.pi4j.component.lcd.LCD;
import com.pi4j.component.lcd.LCDBase;
import com.pi4j.io.gpio.Pin;
import com.pi4j.wiringpi.Lcd;

public class GpioLcdDisplay extends LCDBase implements LCD 
{
    protected int rows;
    protected int columns;
    private int lcdHandle;
    
    public GpioLcdDisplay(int rows, int columns, Pin rsPin, Pin strobePin, Pin... dataPins) {
        this.rows = rows;
        this.columns = columns;
        int bits[] = { 0,0,0,0,0,0,0,0 };
        
        // set wiringPi interface for internal use
        // we will use the WiringPi pin number scheme with the wiringPi library
        com.pi4j.wiringpi.Gpio.wiringPiSetup();        
        
        // seed bit pin address array
        for(int index = 0; index < 8; index++) {
            if(index < dataPins.length)
                bits[index] = dataPins[index].getAddress();
        }
        
        // initialize LCD
        lcdHandle = Lcd.lcdInit(rows, 
                                columns, 
                                dataPins.length, 
                                rsPin.getAddress(), 
                                strobePin.getAddress(), 
                                bits[0], bits[1], bits[2], bits[3], bits[4], bits[5], bits[6], bits[7]);
        
        // verify LCD initialization
        if (lcdHandle == -1) 
            throw new RuntimeException("Invalid LCD handle returned from wiringPi: " + lcdHandle);
    }
    
    @Override
    public int getRowCount() {
        return rows;
    }

    @Override
    public int getColumnCount() {
        return columns;
    }

    @Override
    public void clear() {
        Lcd.lcdClear(lcdHandle);
    }
    
    @Override
    public void setCursorHome() {
        Lcd.lcdHome(lcdHandle);
    }
    
    @Override
    public void setCursorPosition(int row, int column) {
        validateCoordinates(row, column);
        Lcd.lcdPosition(lcdHandle, column, row);
    }

    @Override
    public void write(byte data) {
        Lcd.lcdPutchar(lcdHandle, data);
    }
    
    @Override
    public void write(String data) {
        Lcd.lcdPuts(lcdHandle, data);
    }    
}