Simple Glcd Menu

Other Hardware Displays
1

Hi

I have created three pages for my glcd and they look alright
but what is the simplest way to step through the with a push of a button

cheers Peter

2

I'd use a digitalRead on the pin connected to the button... that seems pretty easy to me... but maybe I missed the intent of your question...

3

Ok

how do i do a simple a simple step loop
i mean buton push goto and stay there :slight_smile: next push goto and stay there..

/Peter

4

Ok got it to work but not as good as I like it to..
here is the code please advise on checking button state without delays

#include <ks0108.h>
#include <Arial14.h>
#include "SystemFont5x7.h"
#include "Wag120x32.h"

const int buttonPin = 2;
int buttonState = 0;
int pag = 0;


void setup(){
  pinMode(buttonPin, INPUT);
  GLCD.Init(NON_INVERTED);
  GLCD.ClearScreen();  
  GLCD.SelectFont(System5x7);
} 


void loop(){


  switch (pag) {
  case 0: 
    introScreen();
    break;
  case 1:  
    page2();
    break;
  case 2:
    page3();
    break;
  case 3:
    page4();
    break;
  case 4:
    reset();
    break;
  } 
   
 }

void introScreen(){
//  GLCD.ClearScreen();
  GLCD.DrawBitmap(Wag120x32, 4,1, BLACK);
  delay(1000);
  GLCD.CursorTo(3,4);
  GLCD.Puts("CPS");
//  delay(1000);
  GLCD.CursorTo(14,7);
  GLCD.Puts("FW 1.01");
  button();
}

void page2(){
//  GLCD.ClearScreen();
  GLCD.CursorTo(3,4);
  GLCD.Puts("Page 2");
  button();
}

void page3(){
//  GLCD.ClearScreen();
  GLCD.CursorTo(3,4);
  GLCD.Puts("Page 3");
  button();
}

void page4(){
//  GLCD.ClearScreen();
  GLCD.CursorTo(3,4);
  GLCD.Puts("Page 4");
  button();
}

void reset(){
pag = 0;
}

void button(){
  buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH) {         
    pag++;
    GLCD.ClearScreen();
    delay(1000);  
  }
}
5

Your code spends a lot of time spinning around re-drawing the same content. You might want to take a look at the attachInterrupt function and use that to detect a button press, and then display your content once. You could then get rid of the delays and your loop() function would be reduced to very little.

Cheers,

6

Can someone please post an little example code besides the one i found references
helps me learn quicker..

thanks
Peter

7

Something along the lines of...

int currentPage = 0;
#define MAX_PAGES 4

void setup()
{
...
attachInterrupt( 0, buttonFunc, HIGH );
...
}

void buttonFunc()
{
  currentPage = ( currentPage + 1 ) % MAX_PAGES;
  showCurrentPage();
}

void showCurrentPage()
{
  switch ( currentPage )
  {
  }
}

In showCurrentPage you call one of your existing functions, but you modify them to remove the delays and the call to your button() function.

Hope that helps,

8

I get an error on this line

currentPage = ( currentPage + 1 % ) MAX_PAGES;

LOG
sketch_mar01a.cpp: In function 'void buttonFunc()':
sketch_mar01a:19: error: expected primary-expression before ')' token
sketch_mar01a:19: error: expected `;' before numeric constant
sketch_mar01a.cpp: In function 'void showCurrentPage()':
sketch_mar01a:39: error: 'reset' was not declared in this scope

cheers

9

Sorry, the mod (%) operator goes outside the brackets. I obviously didn't compile any of that!

10

hmm is not void loop() needed ?

/Peter

11

Yes of course! I didn't write the whole thing for you!

12

Of curse not :wink:

can you explain what hapends at "currentPage = ( currentPage + 1 ) % MAX_PAGES;"

13

It simply increments currentPage and when it gets to the maximum page index (+1) the mod operator forces it back to zero. The mod operator is similar to how you learnt division at school with "remainders" (well, it's how I learnt it anyway). So mod says to divide currentPages by MAX_PAGES and return the remainder. So once currentPages = MAX_PAGES the result is 0. It sounds more complicated than it is.

Cheers,