Arduino/libraries/hd44780/examples/ioClass/hd44780_NTCU20025ECPB_pinIO/ReadWrite/ReadWrite.ino

// vi:ts=4
// ----------------------------------------------------------------------------
// ReadWrite - simple demonstration reading data from LCD
// Created by Bill Perry 2016-08-19
// bperrybap@opensource.billsworld.billandterrie.com
//
// This example code is unlicensed and is released into the public domain
// ----------------------------------------------------------------------------
// 
// This sketch is for Noritake CU-U series displays like the
// Noritake CU20025ECPB-U1J or CU20025ECPB-W1J
// The Noritake CU20025ECPB display is a 20x2 line VFD display.
// It is not a hd44780 display but is nearly fully compatible with a hd44780
// display. The only real difference is the backlight control.
// So while this device is supported by the hd44780 library,
// the subclass will do its best to emulatate hd44780 functions and map
// them to equivalent functionality when possible.
//
// The purpose of the sketch is demonstrate the ability to read data from
// the LCD. As such, it requires an extra Arduino pin to control the R/W LCD
// pin. See below for configuring the Arduino pins used.
//
// Sketch will print the amount of time since the Arduino has been reset
// on the top row and then read the data from the LCD to print it on the
// second row
//
// If there are errors and the arduino supports a built in LED,
// an error status code will blink on the built in LED.
// Error codes:
// (1) lcd device initalization failed
// (2) lcd device does not support reads
// (3) error reading data from lcd device
// (4) error writing data to lcd device
// (5) read data mismatch
//
// See below for configuring the Arduino pins used.
//
// Noritake CU-U series LCD module pins
//  1 - LCD gnd
//  2 - VCC (5v)
//  3 - not connected
//  4 - RS Register Select (rs) --- connect to Arduino pin
//  5 - Read/Write ------ connect to Arduino pin
//  6 - Enable (en) ----- connect to Arduino pin
//  7 - Data 0 (db0) ----
//  8 - Data 1 (db1)     |-------- Not used in 4 bit mode
//  9 - Data 2 (db2)     |
// 10 - Data 3 (db3) ----
// 11 - Data 4 (db4) ---- connect to Arduino pin
// 12 - Data 5 (db5) ---- connect to Arduino pin
// 13 - Data 6 (db6) ---- connect to Arduino pin
// 14 - Data 7 (db7) ---- connect to Arduino pin
//
// ----------------------------------------------------------------------------


#include <hd44780.h>
#include <hd44780ioClass/hd44780_NTCU20025ECPB_pinIO.h> // Arduino pin i/o class header

// declare Arduino pins used for LCD functions
// and the lcd object
// The parameters used by hd44780_NTCU20025ECPB_pinIO are the same as those
// used by the IDE bundled LiquidCrystal library
// note that ESP8266 based arduinos must use the Dn defines rather than
// raw pin numbers.
#if defined (ARDUINO_ARCH_ESP8266)
const int rs=D8, rw=A0, en=D9, db4=D4, db5=D5, db6=D6, db7=D7; // for esp8266 devices
#else
const int rs=8, rw=A0, en=9, db4=4, db5=5, db6=6, db7=7;       // for all other devices
#endif
hd44780_NTCU20025ECPB_pinIO lcd(rs, rw, en, db4, db5, db6, db7);

// LCD geometry
const int LCD_ROWS = 2;
const int LCD_COLS = 20;

void setup()
{
	// initialize LCD with number of columns and rows: 
	if( lcd.begin(LCD_COLS, LCD_ROWS))
	{
		// begin() failed so blink the onboard LED if possible
		fatalError(1);
	}

	// check to see if device can read by attempting to read
	// the lcd status register. If it fails then assume it was
	// because the lcd device does not support reads.
	if(lcd.status() < 0)
	{
		lcd.print("No Read Support");
		fatalError(2);
	}
}

void loop()
{
static unsigned long lastsecs = -1; // pre-initialize with non zero value
unsigned long secs;

	secs = millis() / 1000;

	// see if 1 second has passed
	// so the display is only updated once per second
	if(secs != lastsecs)
	{
		lastsecs = secs; // keep track of last seconds

		// set the cursor position to top line: column 0, row 0
		lcd.setCursor(0, 0);

		// print uptime on lcd device: (time since last reset)
		PrintUpTime(lcd, secs);

		// Now copy the characters from the top line to the 2nd line
		// This is done character by character by:
		// - setting the character position to read
		// - reading a character
		// - setting the character position to write
		// - writing the charcter read
		for(int col = 0; col < LCD_COLS; col++)
		{
		int c;

			lcd.setCursor(col, 0);
			if((c = lcd.read()) < 0) // if a read error, bomb out
			{
				lcd.clear();
				lcd.print("read fail");
				fatalError(3);
			}

			// check for ':' characters in col 2 and 5
			// if not there, consider it a fatal read error
			if((col == 2 || col == 5) && c != ':')
			{
				lcd.clear();
				lcd.print("read fail");
				fatalError(5);
			}

			lcd.setCursor(col, 1);
			if(lcd.write((uint8_t) c) != 1)
			{
				lcd.clear();
				lcd.print("write fail");
				fatalError(4);
			}
		}
	}
}

// PrintUpTime(outdev, secs) - print uptime in HH:MM:SS format
// outdev - the device to send output
//   secs - the total number of seconds uptime
void PrintUpTime(Print &outdev, unsigned long secs)
{
unsigned int hr, mins, sec;

	// convert total seconds to hours, mins, seconds
	mins =  secs / 60;	// how many total minutes
	hr = mins / 60;		// how many total hours
	mins = mins % 60;	// how many minutes within the hour
	sec = secs % 60;	// how many seconds within the minute
		

	// print uptime in HH:MM:SS format
	// Print class does not support fixed width formatting
	// so insert a zero if number smaller than 10
	if(hr < 10)
		outdev.write('0');
	outdev.print((int)hr);
	outdev.write(':');
	if(mins < 10)
		outdev.write('0');
	outdev.print((int)mins);
	outdev.write(':');
	if(sec < 10)
		outdev.write('0');
	outdev.print((int)sec);
}

// fatalError() - loop & blink and error code
void fatalError(int ecode)
{
	hd44780::fatalError(ecode); // does not return
}