TTL input - 3rd states possible?

[flotulopex]

Thanks to both of you,

The Tips & Tricks documentation is cool :-)

I'll have a try with tis stuff.

[flotulopex]

Well,

After a few hours trying to get a positiv result, I just got nothing working.

I would like to read two buttons connected to one pin.

The states are "0" and "1". The third "Z" state is not relevant to me here.

To make sure I have an intermediate level, I use a 2 resistor divider like described in the first post.

Currently, I can't get clear "0" or "1" states.

Any idea?

OSCCON       = %01100000  '4MHz
OPTION_REG   = %10000000  'D I S A B L E PORTB's Pull-Ups for buttons
ANSEL        = %00000000  'Disable Analogue Inputs
TRISB        = %00010000  'Inputs/Outputs
PORTB        = %00000000  'Drive all ports low

MAIN:
    IF PORTB.5 = 0 THEN PORTB.0 = 1
    IF PORTB.5 = 1 THEN PORTB.1 = 1
    PAUSE 1000
    PORTB.0 = 0
    PORTB.0 = 0
    Goto MAIN
    end

I use PORTB.5 of my PIC16F88 for buttons because it is a TTL input only.

[paul borgmeier]

TRISB        = %00010000  'Inputs/Outputs

you have PORTB.4 set as input, not PORTB.5

[flotulopex]

Thanks Paul,

It was again far to obvious to me (the tree in the forest story...).

I'll try again tomorrow and let you know.

Thanks a lot.

[flotulopex]

Well,

I've still got one led always ON.

In my understanding, I should get a state where no Led is ON.

Is this correct?

[skimask]

Well,

I've still got one led always ON.

In my understanding, I should get a state where no Led is ON.

Is this correct?

Show us your code again...

[flotulopex]

<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1504&stc=1&d=117511986 5">

I'm not sure about the ANSEL register. Shall I stay DIGITAL or ANALOG?

I tried both but I get always the same result.

I found this in the data-sheet; it's about the TTL levels.<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1505&stc=1&d=117512006 5">

As far as I can understand, the LOW level will be between Vss and 0,15V and the HIGH level between 2V and Vdd.

Is this correct?