Noob needs some help please...

[mark_s]

This looks like trouble in your code. You gosub to "check_button:" and then goto "button_loop:" if a button is pressed. This creates a case where the gosub never returns, which can cause problems. Beer may help.

check_button:

        if btn_up = 0 OR btn_dwn = 0 OR btn_back = 0 _  ' If any button is pressed 
            OR btn_nxt = 0 OR btn_entr = 0 then         ' Go to button loop

            High lcd_lite                               ' Turn on the LCD Backlight
            goto button_loop
        endif
        return

[Neosec]

That bit has been reworked as follows...

check_button:
        if btn_up = 0 OR btn_dwn = 0 OR btn_back = 0 _  ' If any button is pressed... 
            OR btn_nxt = 0 OR btn_entr = 0 _            ' and the LCD Backlight is on...
            and lcd_lite = 1 then                       ' Then Go to button loop
            goto button_loop
        endif
        if btn_up = 0 OR btn_dwn = 0 OR btn_back = 0 _  ' If any button is pressed...
            OR btn_nxt = 0 OR btn_entr = 0 _            ' and the LCD backlight is not on...
            and lcd_lite = 0 then                       ' Then turn on the backlight...
            high lcd_lite                               ' ...and pause 2 seconds
            pause 2000               ' Holding the button longer than 2 sec. gets you to...
        endif                        ' the button loop VIA the mainloop & check_button and...
        return                       ' IF statement above.

But the GOTO / GOSUB seems ok... At least is seems to be working.

button_loop:
'
if btn_up = 1 and btn_dwn = 1 and btn_back = 1 _  ' If no buttons are pressed go to mainloop...
    and btn_nxt = 1 and btn_entr = 1 then 
 goto mainloop                                 
    endif                                         ' Otherwise continue...

button_set_loop:
if btn_up = 0 then up                   ' If the up button is pressed go to the Up loop
if btn_dwn = 0 then down                ' If the down button is pressed go to the Down loop
if btn_back = 0 then back               ' If the back button is pressed go to the Back loop
if btn_nxt = 0 then forward             ' If the next button is pressed go to the Next loop
if btn_entr = 0 then                    ' If the enter button is pressed go to the Enter loop
        goto enter
    else
        goto button_loop                ' If no buttons are pressed run the button loop again...
endif                                   '   ... which takes you to the main loop.

up:
while btn_up = 0                ' While the Up button is pressed do this loop...                    
pause 30                        ' pause for 30 milliseconds
alrm_set = alrm_set + 1         ' increase alarm set point by one degree F
lcdout $FE, 1, "Alarm Set ", _  ' Display the alarm set point as it's changed
dec (alrm_set),$DF, "F"
pause 300
wend                            ' Repeat, increasing it 1 degree F every ~1/3...
lite_timer = 0                     '   ... second until the switch is released
goto button_loop

down:
while btn_dwn = 0
pau... (and it continues)

The check_button loop returns to the main loop, the button_loop series all end with a GOTO mainloop so it finds its way back. In the code above what I wanted to accomplish was that any button press would turn on the LCD backlight but not increment the variable in button_loop in doing so. The above code work pretty well though I may back off the 2 second pause.
I'm aware that there is much room for improvement in both the code and the hardware... I'm learning as I go. I'm working with a deadline of April 17th so I don't have the time to pretty it up. The hardware is functional with some software work-arounds... Rev B will be awesome!
The IF statement about all the buttons being "1" (not pressed) is likely not necessary since it was a button press that got me there in the first place. Cleaning up that stuff will come later, right now it doesn't break anything and I'm not tight on space yet.

Thanks for looking it over I'm grateful for any tips.

PS I know... interrupts and timers... in Rev B

[Demon]

GOTO out of a subroutine is never a good idea.

Set a flag before GOSUB, change the flag within the subroutine, then check the flag once you've returned and GOTO at that point.

Robert

Edit: it may work this time, but it's a habit you don't want to get into.

[Neosec]

I don't follow... can you give a quick example?

[Charlie]

In most programming languages, when you GOSUB, a number of registers get stored in memory to free them up for use by the subroutine. When you RETURN, those values are put back so the program can continue where it left off. When you GOTO out of a subroutine, the registers are not restored. If you did this when writing a program in a Windows or Linux environment, where the values are store in program RAM, the memory is not released when you GOTO out of the subroutine. This is called a memory leak in your program. Do this often enough, and all the RAM is used and not released until a reboot. It's a good habit to always return from a GOSUB with a RETURN to prevent this.

[spcw1234]

I had a similar routine once and it worked fine, until the 23rd time pressing the button it would cause the pic to reset. As Demon said, just have the button set a bit to 1 then return. Immediately after the gosub check if the bit is a 1 and if it is then goto wherever you want.

[Demon]

I don't follow... can you give a quick example?

Flag=0
Gosub routine
If flag = 1 then goto somewhere
.
.
Routine:
Bla bla bla
If something then flag = 1
Return

Robert

[Neosec]

OK, got it. Thanks to everyone for the input.