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libraries/hd44780/examples/ioClass/hd44780_I2Clcd/Serial2LCD/Serial2LCD.ino

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+// vi:ts=4
+// ----------------------------------------------------------------------------
+// Serial2LCD - simple demonstration printing characters from serial port
+// Created by Bill Perry 2020-06-28
+// bperrybap@opensource.billsworld.billandterrie.com
+//
+// This example code is unlicensed and is released into the public domain
+// ----------------------------------------------------------------------------
+//
+// This sketch is for LCD modules that have a native I2C interface such as
+// PCF2119x, PCF2116, or certain RayStar LCDs rather than those LCD modules that
+// use an i/o expander chip based based backpack.
+//
+// Sketch demonstrates hd44780 how to read a message of characters from 
+// serial port and display it on the LCD.
+// It takes advantage of the hd44780 library automatic line
+// wrapping capability.
+// See the LineWrap sketch for details about line wrapping.
+//
+// NOTE:
+//	These devices usually need external pullups as they typically are not on
+//	the module.
+// WARNING:
+//	Use caution when using 3v only processors like arm and ESP8266 processors
+//	when interfacing with 5v modules as not doing proper level shifting or
+//	incorrectly hooking things up can damage the processor.
+// 
+// Configure LCD_COLS, LCD_ROWS and BAUDRATE if desired/needed
+// Expected behavior of the sketch:
+// - characters received from serial port are displayed on LCD
+// - CR and LF are ignored/dropped
+//
+// If initialization of the LCD fails and the arduino supports a built in LED,
+// the sketch will simply blink the built in LED with the initalization error
+// code.
+//
+// Some 16x1 displays are actually a 8x2 display that have both lines on
+// a single line on the display.
+// If you have one of these displays, simply set the geometry to 8x2 instead
+// of 16x1. 
+
+// include the needed headers.
+#include <Wire.h>
+#include <hd44780.h>						// main hd44780 header
+#include <hd44780ioClass/hd44780_I2Clcd.h>	// i2c LCD i/o class header
+
+// Note, i2c address can be specified or automatically located
+// If you wish to use a specific address comment out this constructor
+// and use the constructor below that specifies the address
+
+// declare the lcd object for auto i2c address location
+hd44780_I2Clcd lcd;
+
+//
+// enter address of LCD.
+// Addresses seen so far include:
+// - 0x3a, 0x3b (PCF2119x)
+// - 0x3c (unknwon chip)
+// - 0x3d (unknwon chip)
+// - 0x3e (unknwon chip)
+// - 0x3f (unknwon chip)
+
+// declare i2c address and constructor for specified i2c address
+//const int i2c_addr = 0x3e;
+//hd44780_I2Clcd lcd(i2c_addr); // use device at this address
+
+// LCD geometry
+// while 16x2 will work on most displays even if the geometry is different,
+// for actual wrap testing of a particular LCD it is best to use the correct
+// geometry.
+const int LCD_COLS = 16;
+const int LCD_ROWS = 2;
+
+const int BAUDRATE = 9600;
+
+void setup()
+{
+int status;
+
+	// initalize Serial port
+	Serial.begin(BAUDRATE);
+
+	// initialize LCD with number of columns and rows: 
+	// hd44780 returns a status from begin() that can be used
+	// to determine if initalization failed.
+	// the actual status codes are defined in <hd44780.h>
+	status = lcd.begin(LCD_COLS, LCD_ROWS);
+	if(status) // non zero status means it was unsuccesful
+	{
+		// begin() failed
+
+		Serial.print("LCD initalization failed: ");
+		Serial.println(status);
+
+		// blink error code using the onboard LED if possible
+		hd44780::fatalError(status); // does not return
+	}
+
+	// turn on automatic line wrapping
+	// which automatically wraps lines to the next lower line and wraps back
+	// to the top when at the bottom line
+	// NOTE: 
+	// noLineWrap() can be used to disable automatic line wrapping.
+	// _write() can be called instead of write() to send data bytes
+	// to the display bypassing any special character or line wrap processing.
+	lcd.lineWrap();
+
+	lcd.print("Serial2LCD"); 
+	if(LCD_ROWS > 1)
+	{
+		lcd.setCursor(0,1);
+		lcd.print("Baud:");
+		lcd.print(BAUDRATE);
+	}
+}
+
+void loop()
+{
+
+	// check to see if characters available
+	// indicating a message is coming in
+	if (Serial.available())
+	{
+		// wait some time for rest of message to arrive
+		delay(100);
+
+		// Clear the display before showing the new message
+    	lcd.clear();
+
+		// print the message on the LCD
+		while (Serial.available() > 0)
+		{
+		char c;
+			c = Serial.read();
+			if(c != '\r' && c != '\n') // drop CR and LF characters
+				lcd.write(c);
+		}
+    }
+}