/*
    Example showing how to use the LiquidCrystal_I2C library.

    Demonstrates:
    - initializing an LCD device
    - setting the cursor
    - printing text
    - turning the text display on and off
    - turning the backlight on and off
    - printing right-justified text
    - printing a variable's value
    - scrolling text laterally
    - using special characters
    - using characters you define yourself
    - modifying only one part of the display
  
    Below is a diagrammatic map of each cursor position in a 16 x 2 (columns x rows) display.
    Each position is notated as a (column,row) coordinate.
    
        (0,0) (1,0) (2,0) ... (15,0)
        (0,1) (1,1) (2,1) ... (15,1)

    example code by Robert Zacharias at Carnegie Mellon University, rzach@cmu.edu
    released by the author to the public domain, November 2018
*/

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

 /* Create an LCD display object called "screen" with I2C address 0x27
    which is 16 columns wide and 2 rows tall. You can use any name you'd like. */
LiquidCrystal_I2C screen(0x27, 16, 2);

int x = 123;

 /* Definition of a custom character called "frowny" which will be used later.
    Each digit is a pixel of the 5x7 array that forms a single character on this display.
    Draw your own at https://maxpromer.github.io/LCD-Character-Creator/ */
byte frowny[] = {
  B00000,
  B11011,
  B11011,
  B00000,
  B00000,
  B01110,
  B10001,
  B00000
}; // (note the extra row of zeros at the bottom)


void setup() {
  // initialize the screen (only need to do this once)
  screen.init();

  // turn on the backlight to start
  screen.backlight();

  // set cursor to home position, i.e. the upper left corner
  screen.home();
  // print the words Hello, world! onto the screen starting at the above cursor position
  screen.print("Hello, world!");

  // move cursor to column 0, row 1
  screen.setCursor(0, 1);
  // print text starting in that position
  screen.print("2nd row text");
  delay(2000); // do nothing for 2 seconds

  // noDisplay() and display() will switch off and on the text
  screen.noDisplay();
  delay(1000);
  screen.display();
  delay(1000);

  // noBacklight() and backlight() will switch off and on the backlight
  screen.noBacklight();
  delay(1000);
  screen.backlight();
  delay(1000);

  screen.clear();

  // autoscroll() will make the text right-justified, noAutoscroll() is regular flow
  screen.autoscroll();
  // therefore, set the cursor one square off of right side of the screen
  screen.setCursor(16, 0);
  screen.print("righttext");
  delay(1000);
  screen.noAutoscroll();

  screen.clear();

  // you can also display a variable on the screen
  screen.home();
  screen.print("x = ");
  screen.print(x);
  delay(1000);

  screen.clear();

  /* You can scroll the display right or left to show long text lines, etc.
     Use screen.scrollDisplayLeft() and ...Right() to move in one-column increments. */
  screen.home();
  screen.print("top long line of text, too much!");
  screen.setCursor(0, 1);
  screen.print("a second line that's also too long");
  for (int i = 0; i < 25; i++) {
    delay(500);
    screen.scrollDisplayLeft();
  }

  screen.clear();

  /* You can create custom characters.
     screen.createChar() below reads the array "frowny" (defined above)
     and loads it into memory location 0 on the LCD screen. */
  screen.createChar(0, frowny);

  /* Use screen.write(codenumber) to print pre-defined non-standard characters.
     See https://learn.robotgeek.com/getting-started/59-lcd-special-characters.html
     for a complete table of available symbols and their codes. */
  screen.home();
  screen.write(126); // right arrow symbol
  screen.print(" ");
  screen.write(243); // infinity symbol
  screen.print(" and beyond!");
  screen.write(233); // to the negative first power symbol

  screen.setCursor(0, 1);
  screen.write(232); // square root symbol
  screen.print("(-1) = ");
  screen.write(0); // "0" is the memory address of the custom character "frowny" from above

  delay(5000);

  screen.clear();
  screen.home();
  screen.print("x = ");
}

void loop() {
  // just count up to show x changing (the rest of the text will remain untouched)
  screen.setCursor(4, 0);
  screen.print(x);
  x++;
  delay(1000);
}

LiquidCrystal_I2C screen(0x27, 16, 2);

/*
  i2c_scanner

  Version 1
    This program (or code that looks like it) can be found in many places.
    For example on the Arduino.cc forum. The original author is not know.
  Version 2, Juni 2012, Using Arduino 1.0.1
     Adapted to be as simple as possible by Arduino.cc user Krodal
  Version 3, Feb 26  2013
    V3 by louarnold
  Version 4, March 3, 2013, Using Arduino 1.0.3
    by Arduino.cc user Krodal.
    Changes by louarnold removed. Scanning addresses changed from 0...127 to 1...119,
    according to the i2c scanner by Nick Gammon http://www.gammon.com.au/forum/?id=10896
  Version 5, March 28, 2013
    As version 4, but address scans now to 127. A sensor seems to use address 120.
  Version 6, November 27, 2015.
    Added waiting for the Leonardo serial communication.

  This sketch tests the standard 7-bit addresses
  Devices with higher bit address might not be seen properly.
*/


#include <Wire.h>


void setup(){
  Wire.begin();
  Serial.begin(9600);
  Serial.println("\nI2C Scanner");
}


void loop() {
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for (address = 1; address < 127; address++ )
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.print(address, HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error == 4)
    {
      Serial.print("Unknown error at address 0x");
      if (address < 16)
        Serial.print("0");
      Serial.println(address, HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);           // wait 5 seconds for next scan
}