help with menu

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1

can anyone help me set up a menu and sub-menu just the simple steps. lcd menu to enter a function and back to lcd menu thanks tom make real simple new at this

2

tom1947:
can anyone help me set up a menu and sub-menu just the simple steps. lcd menu to enter a function and back to lcd menu thanks tom make real simple new at this

Kinda sketchy on parameters?

Here are my assumptions:

  1. functional LCD Display 20x4

  2. functional keypad

Ok.

write a function that scans/polls the keypad, it returns when a key is pressed. Lets assume your keypad has 16 buttons up, down, escape, enter, 0 ..9.

you have a caret on the display pointing to a choice you press, up or down to highlight the choice the Enter to select. Escape if you want move back to a prior menu.

Here is pseudo code:

uint8_t get_key(uint8_t accepted){
// accepted is a bit field that markes allowed keys
// bit 0 = enter
// bit 1 = escape
// bit 2 = up
// bit 3= down;
// bit 4 = numbers

// so   get_key(0xf); would allow all four buttons, but get_key(0xb) would accept escape,enter,down.
do{ // loop until key
  uint8_t key =readkey();  function that actually reads hardware
// lets say key's valid range is 0=no key, 1=enter, 2=escape, 3=up, 4=down, 10='0' .. 19 ='9'
  if(key){// key is not zero, button has been pressed
    if(key<=4){ // in range of control keys.
      if((1 << (key-1))&accepted) return key; // key is allowed
      else raspberry(); // indicate to user a bad key
    else if (accepted&0x10){ // numbers allowed
       if((key>=10)&&(key<=19)) return key; // return digits
       }
  }while true; 
}


void write_caret(uint8_t where){
setCursor(0,where);
write_display('>');
}

void clear_caret(uint8_t where){
setCursor(0,where);
write_display(' ');
}


void subchoice(){
}

void topchoice(){
uint8_t option=0;
unit8_t k;
do{ // menu loop
  clear_display();  
  write_display(" 1 fly\n 2 swim\n 3 hike\n 4 subchoice"); 
  write_caret(option);
   do{ // navigation loop
     k=get_key(0xf); // only want control function keys enter,escape, up, down
     switch(k){
        case 3 : // up
           if (option > 0){
              clear_caret(option);
              option--;
              write_caret(option);
              }
           break;
        case 4 : // down
           if(option <4){
             clear_caret(option);
             option ++
             write_caret(option);
             }
           break;  
        } // switch
   }while((k!=1)$(k!=2)); // enter or escape
if(k==1){ // enter selected
   switch(option){
     case 0 : fly();
       break;
     case 1 : swim();
       break;
     case 2 : hike();
       break;
     case 3 : subchoice();
       break;
     } // end switch
 }while(k!=2); // until escape is pressed.
}

So, this structure can be expanded until you run out of memory. UI is a complex task. I use a menu structure that supports scrollable screens(64 lines), digit entry, next value, prior value, highlighted fields, read only fields, I use a 4x4 pad: left, right, up, down, enter, escape 0..9;
but my menu library has grown larger than a UNO can support. I use a 64K spi Ram for a screen buffer, SPI Flash for menu text.

This task is not simple.

Chuck.

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