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[OT] Anyone make this part?

Started by John Ely May 12, 2004
Hello,

I'm working on a project using several remote I2C ports (PCF8574A),
including the interrupt line. Some of these parts are used to sense
momentary push buttons. I am using electrical switch de-bounce circuits.

These parts generate an interrupt when the input to a port bit changes, so
two interrupts are generated per button press (delayed by the de-bounce
IC). I can handle the second interrupt OK, but it takes extra code (and time).

Does somebody make an 8 bit latch IC with de-bounced inputs or other handy
device to make my job easier?

Or, some other way around my difficulties. :)

Regards,

John




I am working on a similar setup. I am detecting momentary switches. I
use interrupts and I also get them on the up and down press. Since
the switches are momentary when the byte is not zero then process the
interrupt otherwise skip. This setup has worked well for me and I do
not have any debounce problems.

I posted the schematic in the files section IOBOARD.PDF

Also the MCP chip is bidirectional so you can use pins as output also.

JoeT

--- In , John Ely <kwradio@c...> wrote:
> Hello,
>
> I'm working on a project using several remote I2C ports (PCF8574A),
> including the interrupt line. Some of these parts are used to
sense
> momentary push buttons. I am using electrical switch de-bounce
circuits.
>
> These parts generate an interrupt when the input to a port bit
changes, so
> two interrupts are generated per button press (delayed by the de-
bounce
> IC). I can handle the second interrupt OK, but it takes extra code
(and time).
>
> Does somebody make an 8 bit latch IC with de-bounced inputs or
other handy
> device to make my job easier?
>
> Or, some other way around my difficulties. :)
>
> Regards,
>
> John