Problem getting button to turn on LED using 12F675

[Jeff]

I have a noob question. i have been playing with this all night. Im using Microcode 3005 and PBP 2.46. Chip is 12F675. I have checked the usual...blinked the LED's using blink program as a test, and tested the button. All i get is: LED 1 stays on. Schematic is similar to the one above 'cept RC osc, different chip of course.

    CMCON = $1F 
    CMCON = %00000111
    
    GPIO = %00000001                 ' Set GPIO 1 high to turn on LED1
    TRISIO = %00000010               ' set GPIO 4-1 to INputs, RA0 OUTput

Main:
    '*** Test the switch state ***
    if GPIO.0 = 0 then led2 'If switch is pressed then jump to LED2 routine 
 
    GPIO.1 = 1            ' Turn LED1 on
    GPIO.2 = 0            ' Turn LED2 off
    goto Main              ' Jump to the top of the main loop

LED2:
    '*** Turn LED2 on ***
    GPIO.2 = 1            ' LED2 on 
    GPIO.1 = 0            ' LED1 off
    goto Main               ' Jump to the top of the main loop

Any hints on how to troubleshoot this? I don't really want it re-written for me because i am trying to learn but i may change my mind later. thanks.

[Jeff]

I found a mistake, cmcon was the wrong address

ADCON0 = $1F
ADCON0 = %00000000 'TURN OFF CONVERTER

CMCON = $19 'MAKE PINS DIGITAL
CMCON = %00000111

GPIO = %00000001 ' Set GPIO 1 high to turn on LED1
TRISIO = %00000110 ' set GPIO 1 & 2 to INputs, GPIO 0 OUTput

Main:
'*** Test the switch state ***
if GPIO.0 = 0 then led2 'If switch is pressed then jump to LED2 routine

GPIO.1 = 1 ' Turn LED1 on
GPIO.2 = 0 ' Turn LED2 off
goto Main ' Jump to the top of the main loop

LED2:
'*** Turn LED2 on ***
GPIO.2 = 1 ' LED2 on
GPIO.1 = 0 ' LED1 off
goto Main ' Jump to the top of the main loop

[Jeff]

Still doesnt work though. BTW, how do i edit my post??

[cncmachineguy]

Check the pins to make sure you have them set up as digital and not analog inputs.

[mackrackit]

ANSEL turns the ADC on or off on the 12F675.

Use this to disable all ADC
ANSEL=%00000000
CMCON=7

[Jeff]

Thanks guys, you were both right; rookie mistaek on my part. It works now - onward and upward. Now the button turns on LED2 and off LED1. SWEET!

ANSEL = $9F 'FIRST FOUR BITS MAKE IT DIGITAL INPUT
ANSEL = %00000000

ADCON0 = $1F
ADCON0 = %00000000 'TURN OFF CONVERTER

CMCON = $19 'MAKE PINS DIGITAL
CMCON = %00000111


GPIO = %00000010 ' Set GPIO 1 high to turn on LED1
TRISIO = %00000001 ' set GPIO 1 & 2 to INputs, GPIO 0 OUTput

Main:
'*** Test the switch state ***
if GPIO.0 = 0 then led2 'If switch is pressed then jump to LED2 routine

GPIO.1 = 1 ' Turn LED1 on
GPIO.2 = 0 ' Turn LED2 off
goto Main ' Jump to the top of the main loop

LED2:
'*** Turn LED2 on ***
GPIO.2 = 1 ' LED2 on
GPIO.1 = 0 ' LED1 off
goto Main ' Jump to the top of the main loop

[Archangel]

Thanks guys, you were both right; rookie mistake on my part. It works now - onward and upward. Now the button turns on LED2 and off LED1. SWEET!

Welcome back Jeff,
3 years almost. I think what trips up people is this statement,
CMCON = $?? 'MAKE PINS DIGITAL
Which seems to reappear on a regular basis, perhaps copy paste, it should more factually report,
CMCON = $?? 'Disable input Comparators
The ANSEL is the 'MAKE PINS DIGITAL part of the equation, as you found out, My post here is for the future newbies who read this post.