Menu Selection with keypad and LiquidCrystal

Using Arduino Programming Questions
#1

Hello all,

I’m quite new to Arduino so please bear with any of my faux-pas’

Im trying to create an automated brewery controller. I’ve followed the steps for displaying text on an LCD using the LiquidCrystal Libraries and the code compiles correctly.

The only problem I have at the moment is being able to move through on screen menus.

I have a 4 button keypad, and four selections on screen.

What I would like for the program to do is, for example

When button 1 is pressed, a different menu comes up on screen
When button 2 is pressed, another menu different to that comes up.

I can understand the lcd.print and lcd.setCursor stuff just fine, it just need a bit of help with the code for it recognizing when a certain button is pressed then it knows what should come on screen next.

I hope you can help.

Kind Regards

Justin

#2

Use a global variable to store the current menu. Within your loop check your inputs and change the variable's value accordingly. When doing so, update your display.

#3

Hi Ken

Thanks for the reply. Unfortunately, this is my first time programming and I don’t really understand what you have said.

Could you explain it in simpler terms. Or is there any example code you can show me?

What I will say is I am not using the void_loop section

Because the program doesn’t need to loop, I have done it all in the void_setup part.
Is this a bad idea?

Regards

Justin

#4

For example

#include <Keypad.h>
#include <LiquidCrystal.h>

const byte rows = 1;
const byte cols = 4;

char keys[rows][cols] = {
{‘1’,‘2’,‘3’,‘4’}
};

byte rowPins[rows] = {14};
byte colPins[cols] = {15, 16, 17, 18};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, rows, cols);

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
// put your setup code here, to run once:
lcd.begin (20, 4);
lcd.noCursor();
lcd.setCursor (18, 3);
lcd.print (“The Old Paper Mill”);
lcd.setCursor (16, 2);
lcd.print (“Self Contained”);
lcd.setCursor (17, 1);
lcd.print (“Brewing Unit Mk2”);
lcd.setCursor (13, 0);
lcd.print (“Loading!”);
delay(5000);
lcd.clear();
lcd.setCursor (18, 3);
lcd.print (“The Old Paper Mill”);
lcd.setCursor (18, 2);
lcd.print (“Choose a Beer Type”);
lcd.setCursor (19, 1);
lcd.print (“1:Pale || Dark:2”);
lcd.setCursor (19, 0);
lcd.print (“3:Lager || Fruit:4”);

This is what I have so far. I can handle the print, clear screen and setCursor stuff. I just need help with the code for recognising a key press and what to do when a certain key is pressed.
Eg:

if key=1
lcd.clear();
lcd.setCursor(wherever the cursor needs to start);
lcd.print(“Whatever the menu contains”);

if key=2
lcd.clear();
lcd.setCursor(wherever the cursor needs to start);
lcd.print(“Whatever the menu contains”);

And so on an so forth.

Can anyone suggest the code I need to use?

Regards

Justin

#5