lcd_spi.cpp

00001 /*
00002  * mbed LCDWindow library
00003 * Copyright (c) 2010 Hendrik Lipka
00004 * 
00005 * Permission is hereby granted, free of charge, to any person obtaining a copy
00006 * of this software and associated documentation files (the "Software"), to deal
00007 * in the Software without restriction, including without limitation the rights
00008 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00009 * copies of the Software, and to permit persons to whom the Software is
00010 * furnished to do so, subject to the following conditions:
00011 * 
00012 * The above copyright notice and this permission notice shall be included in
00013 * all copies or substantial portions of the Software.
00014 * 
00015 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00016 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00017 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00018 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00019 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00020 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00021 * THE SOFTWARE.
00022 */
00023 
00024 #include "lcd_spi.h"
00025 
00026 #include "SPI.h"
00027 #include "DigitalOut.h"
00028 #include "wait_api.h"
00029 
00030 SPILCDBase::SPILCDBase
00031 (unsigned int columns, unsigned int rows, SPI *spi, PinName enable, PinName rs)
00032 :TextLCDBase(columns,rows)
00033 {
00034     _spi=spi;
00035     _enable=new DigitalOut(enable);
00036     _rs=new DigitalOut(rs);
00037     _enable->write(1);
00038     _spi->format(8,3); // 8 bits, cpol=1, cpha=1 (should be mode 2, but phase seems inverted)
00039     // set SPI frequency at 0.1 MHz
00040     _spi->frequency(100000);
00041 }
00042 
00043 void SPILCDBase::sendByte(const unsigned char byte)
00044 {
00045     _enable->write(0); // enable transfer
00046     wait_us(1);
00047     _spi->write(byte); // send byte over wire
00048     wait_us(20);
00049     _enable->write(1);
00050 }
00051 
00052 void SPILCDBase::sendCmd(const unsigned char cmd)
00053 {
00054     _rs->write(0);
00055     wait_us(1);
00056     sendByte(cmd);
00057     wait_us(1);
00058     _rs->write(1);
00059 }
00060 
00061 void SPILCDBase::sendData(const unsigned char cmd)
00062 {
00063     _rs->write(1);
00064     wait_us(1);
00065     sendByte(cmd);
00066 }