121 lines
3.7 KiB
C++
121 lines
3.7 KiB
C++
// vi:ts=4
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// ----------------------------------------------------------------------------
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// Serial2LCD - simple demonstration printing characters from serial port
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// Created by Bill Perry 2020-06-28
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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 with PCF8574 or MCP23008 chip based backpacks
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//
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// Sketch demonstrates hd44780 how to read a message of characters from
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// serial port and display it on the LCD.
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// It takes advantage of the hd44780 library automatic line
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// wrapping capability.
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// See the LineWrap sketch for details about line wrapping.
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//
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// WARNING:
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// Use caution when using 3v only processors like arm and ESP8266 processors
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// when interfacing with 5v modules as not doing proper level shifting or
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// incorrectly hooking things up can damage the processor.
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//
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// Configure LCD_COLS, LCD_ROWS and BAUDRATE if desired/needed
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// Expected behavior of the sketch:
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// - characters received from serial port are displayed on LCD
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// - CR and LF are ignored/dropped
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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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// NOTE:
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// If the sketch fails to produce the expected results, or blinks the LED,
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// run the included I2CexpDiag sketch to test the i2c signals and the LCD.
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//
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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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// include the needed headers.
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#include <Wire.h>
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#include <hd44780.h> // main hd44780 header
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#include <hd44780ioClass/hd44780_I2Cexp.h> // i2c expander i/o class header
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hd44780_I2Cexp lcd; // declare lcd object: auto locate & config exapander chip
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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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const int BAUDRATE = 9600;
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void setup()
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{
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int status;
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// initalize Serial port
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Serial.begin(BAUDRATE);
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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
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Serial.print("LCD initalization failed: ");
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Serial.println(status);
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// 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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lcd.print("Serial2LCD");
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if(LCD_ROWS > 1)
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{
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lcd.setCursor(0,1);
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lcd.print("Baud:");
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lcd.print(BAUDRATE);
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}
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}
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void loop()
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{
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// check to see if characters available
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// indicating a message is coming in
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if (Serial.available())
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{
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// wait some time for rest of message to arrive
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delay(100);
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// Clear the display before showing the new message
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lcd.clear();
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// print the message on the LCD
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while (Serial.available() > 0)
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{
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char c;
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c = Serial.read();
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if(c != '\r' && c != '\n') // drop CR and LF characters
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lcd.write(c);
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}
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}
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}
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