199 lines
7.3 KiB
C++
199 lines
7.3 KiB
C++
// vi:ts=4
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// ----------------------------------------------------------------------------
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// LineWrap - simple demonstration of automatic linewrap functionality
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// Created by Bill Perry 2017-05-10
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// bperrybap@opensource.billsworld.billandterrie.com
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//
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// This example code is unlicensed and is released into the public domain
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// ----------------------------------------------------------------------------
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//
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// This sketch is for LCDs that are directly controlled with Arduino pins.
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//
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// Sketch demonstrates hd44780 library automatic line wrapping functionality.
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//
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// Background:
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// hd44780 LCDs do not use linear continuous memory for the characters
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// on the lines on the display.
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// This means that simply sending continuous characters to the
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// display will not fill lines and wrap appropriately as might be expected.
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// The hd44780 library solves this issue by adding a line wrapping capability
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// in s/w that can be enabled & disabled.
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// This allows the host to send characters to the display continuously and they
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// will wrap to the next lower line when the end of the visible line has been
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// reached. When on the bottom line it will wrap back to the top line.
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//
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// (Configure LCD_COLS & LCD_ROWS if desired/needed)
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// Expected behavior of the sketch:
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// - display a banner announcing the test.
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// - print the configured LCD geometry
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// - print a long text string to demostrate automatic line wrapping
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// - print lots of characters (slowly) to show how the full wrapping works.
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// (loop)
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//
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// If initialization of the LCD fails and the arduino supports a built in LED,
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// the sketch will simply blink the built in LED with the initalization error
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// code.
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//
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// Special note for certain 16x1 displays:
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// Some 16x1 displays are actually a 8x2 display that have both lines on
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// a single line on the display.
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// If you have one of these displays, simply set the geometry to 8x2 instead
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// of 16x1.
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// In normal sketches, lineWrap() mode will allow this type of display to
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// properly function as a 16x1 display in that it will allow printing up to
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// 16 characters on the display without having to manually set the cursor
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// position to print the right characters on the half of the display.
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// However, when using this 8x2 display as a 16x1 display,
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// scrollDisplayLeft() and scrollDisplayRight() will not work as intended.
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// They will shift the two halves of the display rather than the entire display.
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// This is because the hd44780 chip is doing the shift and chip is hard coded
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// internally for two lines.
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//
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// ----------------------------------------------------------------------------
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// While not all hd44780 use the same pinout, here is the one that most use:
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// pin 1 is the pin closest to the edge of the PCB
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// 1 - LCD gnd
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// 2 - VCC (5v)
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// 3 - Vo Contrast Voltage
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// 4 - RS Register Select (rs)
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// 5 - Read/Write
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// 6 - Enable (en)
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// 7 - Data 0 (db0) ----
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// 8 - Data 1 (db1) |-------- Not used in 4 bit mode
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// 9 - Data 2 (db2) |
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// 10 - Data 3 (db3) ----
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// 11 - Data 4 (db4)
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// 12 - Data 5 (db5)
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// 13 - Data 6 (db6)
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// 14 - Data 7 (db7)
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// 15 - Backlight Anode (+5v)
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// 16 - Backlight Cathode (Gnd)
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// ----------------------------------------------------------------------------
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#include <hd44780.h>
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#include <hd44780ioClass/hd44780_pinIO.h> // Arduino pin i/o class header
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// declare Arduino pins used for LCD functions
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// and the lcd object
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// Note: this can be with or without backlight control:
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// without backlight control:
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// note that ESP8266 based arduinos must use the Dn defines rather than
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// raw pin numbers.
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#if defined (ARDUINO_ARCH_ESP8266)
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const int rs=D8, en=D9, db4=D4, db5=D5, db6=D6, db7=D7; // esp8266 Lolin/Wemos D1 R1 (uno form factor)
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#elif defined(ARDUINO_ARCH_ESP32)
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// note: GPIO12 needs a pulldown resistor
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const int rs=12, en=13, db4=17, db5=16, db6=27, db7=14; // esp32 espduino32 D1 R32 (uno form factor)
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#else
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const int rs=8, en=9, db4=4, db5=5, db6=6, db7=7; // for all other devices
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#endif
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hd44780_pinIO lcd(rs, en, db4, db5, db6, db7);
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//with backlight control:
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// backlight control requires two additional parameters
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// - an additional pin to control the backlight
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// - backlight active level which tells the library the level
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// needed to turn on the backlight.
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// note: If the backlight control pin supports PWM, dimming can be done
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// using setBacklight(dimvalue);
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//
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// WARNING: some lcd keypads have a broken backlight circuit
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// If you have a lcd keypad, it is recommended that you first run the
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// LCDKeypadCheck sketch to verify that the backlight circuitry
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// is ok before enabling backlight control.
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// However, the hd44780_PinIO class will autodetect the issue and
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// work around it in s/w. If the backlight circuitry is broken,
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// dimming will not be possible even if the backlight pin supports PWM.
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//
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#if defined (ARDUINO_ARCH_ESP8266)
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// esp8266 Lolin/Wemos D1 R1 (uno form factor)
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//const int rs=D8, en=D9, db4=D4, db5=D5, db6=D6, db7=D7, bl=D10, blLevel=HIGH;
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#elif defined(ARDUINO_ARCH_ESP32)
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// esp32 espduino32 D1 R32 (uno form factor)
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// note: GPIO12 needs a pulldown resistor
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// Dimming will not work on esp32 as it does not have analogWrite()
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//const int rs=12, en=13, db4=17, db5=16, db6=27, db7=14, bl=5, blLevel=HIGH;
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#else
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//const int rs=8, en=9, db4=4, db5=5, db6=6, db7=7, bl=10, blLevel=HIGH;
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#endif
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//hd44780_pinIO lcd(rs, en, db4, db5, db6, db7, bl, blLevel);
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// LCD geometry
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// while 16x2 will work on most displays even if the geometry is different,
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// for actual wrap testing of a particular LCD it is best to use the correct
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// geometry.
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const int LCD_COLS = 16;
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const int LCD_ROWS = 2;
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void setup()
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{
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int status;
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// initialize LCD with number of columns and rows:
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// hd44780 returns a status from begin() that can be used
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// to determine if initalization failed.
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// the actual status codes are defined in <hd44780.h>
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status = lcd.begin(LCD_COLS, LCD_ROWS);
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if(status) // non zero status means it was unsuccesful
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{
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// begin() failed so blink error code using the onboard LED if possible
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hd44780::fatalError(status); // does not return
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}
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// turn on automatic line wrapping
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// which automatically wraps lines to the next lower line and wraps back
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// to the top when at the bottom line
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// NOTE:
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// noLineWrap() can be used to disable automatic line wrapping.
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// _write() can be called instead of write() to send data bytes
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// to the display bypassing any special character or line wrap processing.
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lcd.lineWrap();
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}
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void loop()
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{
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lcd.clear();
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lcd.print("WrapTest");
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delay(2000);
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lcd.clear();
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//print the configured LCD geometry
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lcd.print(LCD_COLS);
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lcd.print("x");
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lcd.print(LCD_ROWS);
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delay(3000);
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lcd.clear();
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// print a long text string
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// without line wrapping enabled, the text would not wrap properly
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// to the next line.
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if(LCD_COLS == 8)
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lcd.print("A long text line");
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else
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lcd.print("This is a very long line of text");
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delay(3000);
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lcd.clear();
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// now print 2 full displays worth of characters to show
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// the full wrapping.
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lcd.cursor(); // turn on cursor so you can see where it is
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char c = '0'; // start at the character for the number zero
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for(int i = 2*LCD_COLS*LCD_ROWS; i; i--)
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{
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lcd.print(c++);
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delay(200); // slow things down to watch the printing & wrapping
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if(c > 0x7e) // wrap back to beginning of printable ASCII chars
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c = '!';
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}
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delay(3000);
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lcd.noCursor(); // turn off cursor
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}
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