Re: [avr-gcc-list] external interrupt use

[Jamie Morken]

----- Original Message -----
From: "Ilhom Djalilov" <address@hidden>
To: <address@hidden>
Sent: Monday, February 23, 2004 9:21 PM
Subject: Re: [avr-gcc-list] external interrupt use


> Hello Jamie,
>
> Tuesday, February 24, 2004, 7:59:01 AM, you wrote:
>
> JM> Hi all,
>
> JM> I have 6 digital signals that I need to be able to trigger an
interrupt on
> JM> the falling edge and rising edge for all of them, but I am short 2
external
> JM> interrupts.  Is there a simple way to detect the 6 signals
rising/falling
> JM> edges with 4 interrupts and some additional circuitry?  I have thought
about
> JM> using diodes to AND some of the signals but this only works for
positive
> JM> edges I think.
>
>               INT0                INT1
>        pullup  |                   |   pulldown
> +5 <---/\/\/\--o-|>|---o-----|>|---o---/\/\/\--------> GND
>                |       |           |
>                |      signal 1     |
>                o-|>|---o-----|>|---o
>                        |
>                       signal 2
>

I don't see the purpose of doing this as it only works with 2 signals, and
ties up two external interrupts.  If you have three signals with 6 diodes,
and two signals low and one high, then switch to two high and one low, the
INT0 and INT1 lines won't detect this change I don't think.

cheers,
Jamie



> Best regards,
>  Ilhom
>
>
>
> _______________________________________________
> avr-gcc-list mailing list
> address@hidden
> http://www.avr1.org/mailman/listinfo/avr-gcc-list
>



_______________________________________________
avr-gcc-list mailing list
address@hidden
http://www.avr1.org/mailman/listinfo/avr-gcc-list