PortA as Inputs in PIC16F628A program

[JackBauer2424]

I'm working on the following simple piece of code that serouts the states (high or low) of its PortA and PortB pins. Right now it's successfully sending the PortB states but I'm not getting accurate PortA states. Please tell me what I'm doing wrong and feel free to comment if you think there's a better way to do this.
Thanks

SYMBOL PortA = 5
SYMBOL TrisA = $85
SYMBOL PortB = 6
SYMBOL TrisB = $86
SYMBOL CmCom = $1F
SYMBOL Ready = 2
SYMBOL Load = 1
SYMBOL Xmit = 3

POKE TrisA,%11111111 'only using PORTA.0-PORTA.3 in real application
POKE TrisB,%11110101
POKE CmCom,%00000111


Main:
IF Pin2 = 1 THEN Transmit

GOTO Main


Transmit:
HIGH Load
PEEK PortB,B0
PEEK PortA,B1

LOW Load

SEROUT Xmit, N9600, ("A","B",B0,B1) '"A" and "B" are qualifiers
GOTO Main

'End of Program

[sougata]

Hi,

Your chip has an onboard voltage comparator. You can turn this off by inserting:

CMCON = 7

This may solve your problem.

Regards

Sougata

[mramos]

The books shows

Symbol CMCON = $1f
Poke COCON ,7

or

poke $1f,7 (one line version)

[mister_e]

As i can't say how read from a pin in PBC and you have correctly POKE the CMCON register in your code example in the first post, my question is... how do you connect your switch to the PORT? Any pull-up/pull-down resistor?

I guess one day i'll buy PBC myself too just for fun

[mister_e]

let's do a try... sorry if i'm wrong.. i try

Main: 
    peek PORTA,B0
    if Bit1=1 then transmit ' iF PORTA.1=1 then transmit
    GOTO Main

[mramos]

Main: 
    peek PORTA,B0
    if Bit1=1 then transmit ' iF PORTA.1=1 then transmit
    GOTO Main

The peek reads porta into B0 (you did not include where you have porta defined (unless PB has it defined.. I doubt it, maybe PBP does, I made an include to drop in my code since BP is not a complete product). B0 is byte 0 in the chip.

Now that it is in B0, you need to IF against B0. So you can AND it (as it is a byte not a bit) with %00000010.