Help with example button program

[keithv]

Any ideas how I can improve this code? I'm trying to use a push button switch to toggle between 2 LEDs. For the most part it works, but the switch does not debounce very well. I'm actually trying to toggle between turning an LED on and turning a relay off, which is why one of the variables is named LATCH1, but for testing purposes I'm just using 2 LEDs.



' Name : BUTTONTEST.pbp
' Compiler : PICBASIC PRO Compiler 3.0
' Assembler : PM
' Target PIC : 8-pin PIC12F675 or similar type
' Hardware : Kee
' Oscillator : 4MHz internal
' Keywords : HIGH, LOW
' Description : PICBASIC PRO program to show button press on LED.

#config
__CONFIG _CP_OFF & _WDT_OFF & _BODEN_ON & _PWRTE_ON & _INTRC_OSC_NOCLKOUT & _MCLRE_OFF & _CPD_OFF
#endconfig

Define OSCCAL_1K 1 ' PIC12F675, Calibrate internal oscillatordefine MCLRE_OFF
define BUTTON_PAUSE 65

LED1 Con 0 ' Alias GPIO.0 to LED1
LATCH1 con 1 'Alias GPIO.1 to LATCH1
PB1 Var GPIO.2 ' Alias GPIO.2 to push button
B1 var byte 'Working buffer for switch1 button command

ANSEL = 0 ' Set all digital
CMCON = 7 ' Analog comparators off
clear
low LED1 'Begin program with LED1 off
high LATCH1 'Begin program with relay1 in bypass

main:
switch1:

button PB1, 0, 40, 5, B1, 0, main
toggle LATCH1
toggle LED1

Goto main ' Do it forever

End

[HenrikOlsson]

Hi,
If it's really not debouncing properly - even with 65ms worth of "debounce time", you've got to have a really bouncy switch... :-)

Are you sure that it's not the autorepeat feature you're seeing? If you change the value 40 in your example to 255 it will still debounce but not autorepeat - according to the manual.

/Henrik.

[Acetronics2]

Hi,

I'm not so sure of:

button PB1, 0, 40, 5, B1, 0, main

I'd try ...

...
B1 = 0 ; always think to place it just before " button " command ...
button PB1, 0, 255, 0, B1, 1,yes 
no:
Pause 20 ; pace the scanning ... not compulsory
goto main
yes:
toggle LATCH1
toggle LED1
...

that's the way It works for me for years in such a use ... note I think ( and observed ) the debouncing only occurs if condition is true (1) ...
so, sometimes, you have to "twist" the test somewhat ...

Alain