Variable Questions

railroad signal

Hello everybody.
I am trying to understand variables. What I am trying to accomplish.When I momentarily push a button I would like to register that the push buttonhas or has not been pressed in the DEBUG HOME. I am having problems. Cannot getthe input to communicate with the variable. What is your recommendations. Thank you.

' {$STAMP BS2}' {$PBASIC 2.5}
hold VAR Bit
DO
DEBUG HOME
DEBUG ? IN0
DEBUG ? hold
INPUT 0
LOOP

Tracy Allen

How do you have the button hooked up to pin p0?

The program looks okay. The variable "hold" doesn't do anything. A simpler test program is,

DO
DEBUG in0+48 ' prints 0 or 1
PAUSE 100
LOOP

That simply shows a continuous line, 00000011111100000011...

Sapphire

If your input is normally LOW and goes HIGH when you press the button, use this:

[SIZE=2][FONT=courier new][COLOR=#000000]' {$STAMP BS2}
' {$PBASIC 2.5}[/COLOR]
[COLOR=#000000]
hold VAR Bit
hold = 0

INPUT 0[/COLOR]
[COLOR=#000000]
DO[/COLOR]
[COLOR=#000000]  hold = hold | IN0
  DEBUG HOME
[/COLOR][COLOR=#000000]  DEBUG ? IN0
[/COLOR][COLOR=#000000]  DEBUG ? hold
[/COLOR][COLOR=#000000]LOOP[/COLOR]
[/FONT][/SIZE]

But if your input is normally HIGH and goes LOW when you press the button, then use this:

[FONT=courier new][SIZE=2][COLOR=#000000]' {$STAMP BS2}
' {$PBASIC 2.5}[/COLOR]
[COLOR=#000000]
hold VAR Bit
hold = 1

INPUT 0[/COLOR]
[COLOR=#000000]
DO
  hold = hold & IN0
[/COLOR][COLOR=#000000]  DEBUG HOME
[/COLOR][COLOR=#000000]  DEBUG ? IN0
[/COLOR][COLOR=#000000]  DEBUG ? hold
[/COLOR][COLOR=#000000]LOOP[/COLOR]
[/SIZE][/FONT]

Once you press the button, hold will retain the state. You will need to clear/reset hold later in your program to capture another button press.