test code megasquirt and digole lcd
Dependencies: FatFileSystem mbed
Diff: TextLCD.cpp
- Revision:
- 0:7ea8f0d27a4f
diff -r 000000000000 -r 7ea8f0d27a4f TextLCD.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/TextLCD.cpp Fri Nov 27 16:32:41 2015 +0000 @@ -0,0 +1,188 @@ +/* draft mbed TextLCD + * (c) 2007/8, sford + */ + +#include "TextLCD.h" + +#include "mbed.h" + +using namespace mbed; + +/* + * 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 + */ + + +//wait(0.05); + +TextLCD::TextLCD(PinName rs, PinName rw, PinName e, PinName d0, PinName d1, + PinName d2, PinName d3, int columns, int rows) : _rw(rw), _rs(rs), + _e(e), _d(d0, d1, d2, d3), _columns(columns), _rows(rows) { + + _rows = 4; + _columns = 20; +wait(0.05); + _rw = 0; + _e = 1; + _rs = 0; // command mode +wait(0.05); + // 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++) { + writeNibble(0x3); + wait(0.005); // this command takes 1.64ms, so wait for it + } + wait(0.1); + writeNibble(0x2); // 4-bit mode +wait(0.001); + writeCommand(0x28); // Function set 001 BW N F - - +wait(0.001); + writeCommand(0x0C); + wait(0.001); + writeCommand(0x6); // Cursor Direction and Display Shift : 0000 01 CD S (CD 0-left, 1-right S(hift) 0-no, 1-yes + cls(); +} + + + +int TextLCD::_putc(int value) { + if(value == '\n') { + newline(); + } else { + writeData(value); + } + return value; +} + +int TextLCD::_getc() { + return 0; +} + +void TextLCD::newline() { + _column = 0; + _row++; + if(_row >= _rows) { + _row = 0; + } + locate(_column, _row); +} + +void TextLCD::locate(int column, int row) +{ + /* if(column < 0 || column >= _columns || row < 0 || row >= _rows) { + ERROR("locate(%d,%d) out of range on %dx%d display", column, row, _columns, _rows); + return; + }*/ + + _row = row; + _column = column; + int address=0; + + if (_rows > 2) { + // row 0 : 0x0->0x13 + // row 1 : 0x40->0x53 + // row 2 : 0x14->0x27 + // row 3 : 0x54->0x67 + + switch (_row) { + case (0) : address = 0x80 + _column; + break; + case (1) : address = 0xc0 + _column; + break; + case (2) : address = 0x94 + _column; + break; + case (3) : address = 0xd4 + _column; + break; + } + + } + else { + // memory starts at 0x80, and is 40 chars long per row + address = 0x80 + (_row * 40) + _column; + } + + writeCommand(address); +} + + +void TextLCD::rows(int rows) { + _rows = rows; +} + + +void TextLCD::columns(int columns) { + _columns = columns; +} + + + + +void TextLCD::cls() { + writeCommand(0x01); // Clear Display + wait(0.00164f); // This command takes 1.64 ms + locate(0, 0); +} + +void TextLCD::reset() { + cls(); +} + +void TextLCD::clock() { + wait(0.00010); + _e = 0; + wait(0.00010); // most instructions take 40us + _e = 1; +} + +void TextLCD::writeNibble(int value) { + _d = value; + clock(); +} + +void TextLCD::writeByte(int value) { + writeNibble(value >> 4); + writeNibble(value >> 0); +} + +void TextLCD::writeCommand(int command) { + _rs = 0; + writeByte(command); +} + +void TextLCD::writeData(int data) { + _rs = 1; + writeByte(data); + _column++; + if(_column >= _columns) { + newline(); + } +}