display funciona!
Dependents: 2018_I2C_LCD_03 TBI_FIAT_FEEDFORWARD Ignition Can_between_NUCLEOS_LCD ... more
Fork of TextLCD by
TextLCD.cpp
- Committer:
- simon
- Date:
- 2010-05-22
- Revision:
- 0:edfb85c53631
- Child:
- 1:ac48b187213c
File content as of revision 0:edfb85c53631:
/* mbed TextLCD Library, 4-bit 2x16 * Copyright (c) 2007-2010, sford * * 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. */ #include "TextLCD.h" #include "mbed.h" /* * useful info found at http://www.a-netz.de/lcd.en.php * * Initialisation * ============== * * After attaching the supply voltage/after a reset, the display needs to be brought in to a defined state * * - wait approximately 15 ms so the display is ready to execute commands * - Execute the command 0x30 ("Display Settings") three times (wait 1,64ms after each command, the busy flag cannot be queried now). * - The display is in 8 bit mode, so if you have only connected 4 data pins you should only transmit the higher nibble of each command. * - If you want to use the 4 bit mode, now you can execute the command to switch over to this mode now. * - Execute the "clear display" command * * Timing * ====== * * Nearly all commands transmitted to the display need 40us for execution. * Exceptions are the commands "Clear Display and Reset" and "Set Cursor to Start Position" * These commands need 1.64ms for execution. These timings are valid for all displays working with an * internal clock of 250kHz. But I do not know any displays that use other frequencies. Any time you * can use the busy flag to test if the display is ready to accept the next command. * * _e is kept high apart from calling clock * _rw is kept 0 (write) apart from actions that uyse it differently * _rs is set by the data/command writes */ TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, PinName d2, PinName d3) : _rw(rw), _rs(rs), _e(e), _d(d0, d1, d2, d3) { _rw = 0; _e = 1; _rs = 0; // command mode // Should theoretically wait 15ms, but most things will be powered up pre-reset // so i'll disable that for the minute. If implemented, could wait 15ms post reset // instead // wait(0.015); // 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); wait(0.00164); // this command takes 1.64ms, so wait for it } writeByte(0x2); // 4-bit mode 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 address = 0x80 + (row * 40) + column; // memory starts at 0x80, and is 40 chars long per row writeCommand(address); writeData(c); } int TextLCD::columns() { return 16; } int TextLCD::rows() { return 2; } void TextLCD::writeByte(int value) { _d = value >> 4; wait(0.000040f); // most instructions take 40us _e = 0; wait(0.000040f); _e = 1; _d = value >> 0; wait(0.000040f); _e = 0; wait(0.000040f); // most instructions take 40us _e = 1; } void TextLCD::writeCommand(int command) { _rs = 0; writeByte(command); } void TextLCD::writeData(int data) { _rs = 1; writeByte(data); }