Andrew Reed
/
CITY1082-TFT-basic
Basic TFT display program for CITY082
Diff: TextLCD.cpp
- Revision:
- 1:402b32a1025f
- Parent:
- 0:6beb6f498640
--- a/TextLCD.cpp Mon Aug 09 14:17:02 2010 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,193 +0,0 @@ -/* mbed I2CTextLCD Library, for a 4-bit LCD driven by I2C and a PCF8574 - * Copyright (c) 2007-2010, sford, rcocking - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ - -/* This is a hack of Simon Ford's direct-driven TextLCD code. -* It should be refactored to extract a common superclass -* but my C++ isn't yet good enough :) -* -* The code assumes the following connections between the PCF8574 -* and the LCD -* -* nc - D0 -* nc - D1 -* nc - D2 -* nc - D3 -* P0 - D4 -* P1 - D5 -* P2 - D6 -* P3 - D7 -* P4 - E -* P5 - nc -* P6 - nc -* P7 - RS -* gnd - R/W -* -* D0-3 of the LCD are not connected because we work in 4-bit mode -* R/W is hardwired to gound, as we only ever write to the LCD -* A0-2 on the PCF8574 can be set in any combination; you will need to modify -* the I2C address in the I2CTextLCD constructor. -* Remember that the mbed uses 8-bit addresses, which should be -* in the range 0x40-0x4E for the PCF8574 -*/ -#include "TextLCD.h" -#include "mbed.h" - -TextLCD::TextLCD(PinName sda, PinName scl, int i2cAddress, LCDType type) : _i2c(sda, scl), - _type(type) { - _i2cAddress = i2cAddress; - wait(0.015); // Wait 15ms to ensure powered up - - // send "Display Settings" 3 times (Only top nibble of 0x30 as we've got 4-bit bus) - for (int i=0; i<3; i++) { - writeByte(0x3, false); - wait(0.00164); // this command takes 1.64ms, so wait for it - } - writeByte(0x2, false); // 4-bit mode - wait(0.000040f); // most instructions take 40us - - writeCommand(0x28); // Function set 001 BW N F - - - writeCommand(0x0C); - writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes - cls(); -} - -void TextLCD::character(int column, int row, int c) { - int a = address(column, row); - writeCommand(a); - writeData(c); -} - -void TextLCD::cls() { - writeCommand(0x01); // cls, and set cursor to 0 - wait(0.00164f); // This command takes 1.64 ms - locate(0, 0); -} - -void TextLCD::locate(int column, int row) { - _column = column; - _row = row; -} - -int TextLCD::_putc(int value) { - if (value == '\n') { - _column = 0; - _row++; - if (_row >= rows()) { - _row = 0; - } - } else { - character(_column, _row, value); - _column++; - if (_column >= columns()) { - _column = 0; - _row++; - if (_row >= rows()) { - _row = 0; - } - } - } - return value; -} - -int TextLCD::_getc() { - return -1; -} - -void TextLCD::writeI2CByte(int data) { - // equivalent to writeI2CByte - char * cmd = new char[1]; - cmd[0] = data; - _i2c.write(_i2cAddress, cmd, 1); -} - -void TextLCD::writeNibble(int data, bool rs) { - if (rs) { - data = data | RS_ON; // set rs bit - } - data |= E_ON; // E on - writeI2CByte(data); - data ^= E_ON; // E off - wait_us(1); - writeI2CByte(data); - wait_us(1000); -} - -void TextLCD::writeByte(int data, bool rs) { - writeNibble(data >> 4, rs); - writeNibble(data & 0x0F, rs); -} - -void TextLCD::writeCommand(int command) { - // equivalent to ard commandWrite - writeByte(command, false); -} - -void TextLCD::writeData(int data) { - - writeByte(data, true); -} - -int TextLCD::address(int column, int row) { - switch (_type) { - case LCD20x4: - switch (row) { - case 0: - return 0x80 + column; - case 1: - return 0xc0 + column; - case 2: - return 0x94 + column; - case 3: - return 0xd4 + column; - } - case LCD16x2B: - return 0x80 + (row * 40) + column; - case LCD16x2: - case LCD20x2: - default: - return 0x80 + (row * 0x40) + column; - } -} - -int TextLCD::columns() { - switch (_type) { - case LCD20x4: - case LCD20x2: - return 20; - case LCD16x2: - case LCD16x2B: - default: - return 16; - } -} - -int TextLCD::rows() { - switch (_type) { - case LCD20x4: - return 4; - case LCD16x2: - case LCD16x2B: - case LCD20x2: - default: - return 2; - } -}