A_hello_menu.ino

This is the get started example demonstrating how to create a menu of two screens with dynamically changing information.

/*
* LiquidMenu library - hello_menu.ino
*
* This is the get started example demonstrating how to create
* a menu of two screens with dynamically changing information.
*
* The first screen shows some static text. The second screen
* shows the reading of analog pin A1. To display a changing
* variable on the LCD, simply put the variable in the LiquidLine
* constructor. In this case the LiquidLine object is "analogReading_line"
* and the variable is "analogReading". This line is on the second
* screen. The value of the analog pin is read every second and if
* it has changed the display is updated with the new value. The
* menu cycles through its two screens every five seconds.
*
* The circuit:
* https://github.com/VasilKalchev/LiquidMenu/blob/master/examples/A_hello_menu/hello_menu.png
* - LCD RS pin to Arduino pin 12
* - LCD E pin to Arduino pin 11
* - LCD D4 pin to Arduino pin 5
* - LCD D5 pin to Arduino pin 4
* - LCD D6 pin to Arduino pin 3
* - LCD D7 pin to Arduino pin 2
* - LCD R/W pin to ground
* - LCD VSS pin to ground
* - LCD VDD pin to 5V
* - 10k ohm potentiometer: ends to 5V and ground, wiper to LCD V0
* - 150 ohm resistor from 5V to LCD Anode
* - LCD Cathode to ground
* - ----
* - some analog input to Arduino pin A1 (unconnected also works)
*
* Created July 24, 2016
* by Vasil Kalchev
*
* https://github.com/VasilKalchev/LiquidMenu
*
*/
// The LCD library
#include <LiquidCrystal.h>
// The menu wrapper library
#include <LiquidMenu.h>
// Pin mapping for the display:
const byte LCD_RS = 12;
const byte LCD_E = 11;
const byte LCD_D4 = 5;
const byte LCD_D5 = 4;
const byte LCD_D6 = 3;
const byte LCD_D7 = 2;
//LCD R/W pin to ground
//10K potentiometer wiper to VO
LiquidCrystal lcd(LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7);
/*
* Variable 'analogReading' is later configured to
* be printed on the display. 'lastAnalogReading'
* is used to check if the variable has changed.
*/
const byte analogPin = A1;
unsigned short analogReading = 0;
unsigned short lastAnalogReading = 0;
/*
* Variables used for periodic execution of code. The first one is the period
* in milliseconds and the second one is the last time the code executed.
*/
unsigned int period_check = 1000;
unsigned long lastMs_check = 0;
unsigned int period_nextScreen = 5000;
unsigned long lastMs_nextScreen = 0;
/*
* LiquidLine objects represent a single line of text and/or variables
* on the display. The first two parameters are the column and row from
* which the line starts, the rest of the parameters are the text and/or
* variables that will be printed on the display. They can be up to four.
*/
// Here the line is set to column 1, row 0 and will print the passed
// string and the passed variable.
LiquidLine welcome_line1(1, 0, "LiquidMenu ", LIQUIDMENU_VERSION);
// Here the column is 3, the row is 1 and the string is "Hello Menu".
LiquidLine welcome_line2(3, 1, "Hello Menu");
/*
* LiquidScreen objects represent a single screen. A screen is made of
* one or more LiquidLine objects. Up to four LiquidLine objects can
* be inserted from here, but more can be added later in setup() using
* welcome_screen.add_line(someLine_object);.
*/
// Here the LiquidLine objects are the two objects from above.
LiquidScreen welcome_screen(welcome_line1, welcome_line2);
// Here there is not only a text string but also a changing integer variable.
LiquidLine analogReading_line(0, 0, "Analog: ", analogReading);
LiquidScreen secondary_screen(analogReading_line);
/*
* The LiquidMenu object combines the LiquidScreen objects to form the
* menu. Here it is only instantiated and the screens are added later
* using menu.add_screen(someScreen_object);. This object is used to
* control the menu, for example: menu.next_screen(), menu.switch_focus()...
*/
LiquidMenu menu(lcd);
void setup() {
Serial.begin(250000);
pinMode(analogPin, INPUT);
lcd.begin(16, 2);
// This is the method used to add a screen object to the menu.
menu.add_screen(welcome_screen);
menu.add_screen(secondary_screen);
}
void loop() {
// Periodic reading of the analog pin.
if (millis() - lastMs_check > period_check) {
lastMs_check = millis();
analogReading = analogRead(analogPin);
/*
* Check if the analog value have changed
* and update the display if it has.
*/
if (analogReading != lastAnalogReading) {
lastAnalogReading = analogReading;
menu.update();
}
}
// Periodic switching to the next screen.
if (millis() - lastMs_nextScreen > period_nextScreen) {
lastMs_nextScreen = millis();
menu.next_screen();
}
}