Making a menu selection

[lerameur]

Hi,

I am trying to make a menu selection SUB that will not exit until select button is pressed. I am using the PIC18F4550

Selection var PortC.6
Next1 var PortC.7
'/////////////////////////////////////   
'///////  GetModeOfOperation  ////////
'/////////////////////////////////////
GetModeOfOperation:

	Lookup Op_Mode, [55,65],Operation_Mode
	
	Select Case Operation_Mode
	Case 55 								
		lcdout $FE,1,  " Charger Mode "
	Case 65 								
		lcdout $FE,1,  " Recycle Mode"
	End Select
	
		lcdout $FE,$C0, "Next or Select"
		pause 200
		
		if Selection=1 then return
		if Next1=1 then Op_Mode = Op_Mode + 1
		if Op_Mode > 1 then Op_Mode = 0
		Gosub GetModeOfOperation

Return

The problem, is that my sub routine exits (return) after 4 seconds while nothing has been pressed.

[cncmachineguy]

Hi,

I am trying to make a menu selection SUB that will not exit until select button is pressed. I am using the PIC18F4550

Selection var PortC.6
Next1 var PortC.7
'/////////////////////////////////////   
'///////  GetModeOfOperation  ////////
'/////////////////////////////////////
GetModeOfOperation:

	Lookup Op_Mode, [55,65],Operation_Mode
	
	Select Case Operation_Mode
	Case 55 								
		lcdout $FE,1,  " Charger Mode "
	Case 65 								
		lcdout $FE,1,  " Recycle Mode"
	End Select
	
		lcdout $FE,$C0, "Next or Select"
		pause 200
		
		if Selection=1 then return
		if Next1=1 then Op_Mode = Op_Mode + 1
		if Op_Mode > 1 then Op_Mode = 0
		Gosub GetModeOfOperation

Return

The problem, is that my sub routine exits (return) after 4 seconds while nothing has been pressed.

I just learned today that in th 18's you can overflow the stack. I don't really know the what happens when you do, but I suspect a "reset" maybe. Anyhow, I think the gosub needs to be a goto. otherwise you just keep calling itself without a return. everytime it saves PC to the stack, but never reads it back.

[lerameur]

ok wow work great now, thank you

K

[Jerson]

This should help you.

a menu selection SUB that will not exit until select button is pressed.

Selection var PortC.6

Next1 var PortC.7

'/////////////////////////////////////   
'///////  GetModeOfOperation  ////////
'/////////////////////////////////////
GetModeOfOperation:
     while Selection = 0           ' exit when selection becomes 1

	Lookup Op_Mode, [55,65],Operation_Mode
	
	Select Case Operation_Mode
	Case 55 								
		lcdout $FE,1,  " Charger Mode "
	Case 65 								
		lcdout $FE,1,  " Recycle Mode"
	End Select
	
		lcdout $FE,$C0, "Next or Select"
		pause 200
		
		if Next1=1 then Op_Mode = Op_Mode + 1
		if Op_Mode > 1 then Op_Mode = 0
     wend
     Return