- did you banksel ADCON1 before you set it to 0x6 ?

- assuming you've properly disabled ADC on the pins, are you sure they're
inputs? TRISC bits are High for inputs on PORTA on F877.

- what is connected to PORTA? are you sure any of the lines are *ever* going
high?

- are you sure your LEDs are wired up properly??

> -----Original Message-----
> From: Aubrey McIntosh, Ph.D.
> [mailto:Aubrey.McIntosh@ALUMNI.UTEXAS.NET]
> Sent: 09 February 2004 16:32
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [PIC:] Reading PortA on 16F877
>
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
>
> I want to read either PortA or PortE on a 16F877 chip as
> digital input.
>
> I have read the PortA, PortE, and A/D sections of 30292c.pdf
> In particular, I have read p113.
> On page 218, there is an example to use PortA.  I have not
> done the CLRF PortA shown in the example, but otherwise
> comply.  I will try this in the next cycle.
>
> I have set ADCON1 to 0x06 and verified this with read and
> display to LEDs. I have set  and verified TRISA to 0x3F
>
> I do a very simple
>          banksel PORTA
>          movf    PORTA,w
>          banksel PORTD           ;home of the LEDs.
>          movwf   PORTD
>
> The LEDs are always dark.  I have success with PORTC as an input.
>
> Thoughts?
>
>
> - --
> Aubrey McIntosh, Ph.D.
>
>
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> =kizK
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>
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