Hi Raymond!

You can use PCF8574 device from Philips it's an I/O port expander with 8 bits
or anothe PCF857X device with 16 I/O lines and
can communicate via i2c with your PIC16F877.I used in my project and works
good!If you need I can give you some test routine!

Regards
Miki




Raymond Choat wrote:

> My project is using a 16F877. I need to hook 12 switches/buttons to it.
> These switches/buttons are 4 ft away. I have 4 pins on the 16F877 that are
> still not used. Would it be best to use a multiplexer chip or IC2 to another
> Pic reading the switches and buttons. Will a multiplexer allow more than one
> switch to be pressed at the same time? Has anyone done this that has
> examples?
> Many Thanks
> Wrong Way Ray (Raymond Choat)
>
> ----- Original Message -----
> From: "Sam Linder" <SamL@IN-INC.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Wednesday, July 11, 2001 7:46 AM
> Subject: Re: [PIC]: Dallas DS1305
>
> > John:
> > I've attached a zip file containing the Dallas DS1305 code to this
> message.
> > It contains 4 files (RTCcode.c, rtc.h, pc16f877.8, p16f877.h).
> >
> > For other PIC listers who may be uncomfortable with opening zip files from
> > people you don't know, I don't blame you and I suggest you simply delete
> > this message.
> >
> > John and any others interested in the code - if you prefer I resend the
> > files in plain text directly to you, please let me know and I will be glad
> > to do so.
> >         Sam....
> >
> > -----Original Message-----
> > From: John [mailto:jsand@PIXIE.CO.ZA]
> > Sent: Wednesday, July 11, 2001 5:32 AM
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: [PIC]: Dallas DS1305
> >
> >
> > Hello Sam & PIC.ers,
> >
> > If you feel free to post it & it's not too long, please.
> > Otherwise you might send it direct to me.
> >
> > I think you'll be saving me a lot of time/trouble in
> > my AD7715 job.
> >
> >         best regards,   John
> >
> >
> > >Date:    Tue, 10 Jul 2001 08:31:29 -0700
> > >From:    Sam Linder <SamL@IN-INC.COM>
> > >Subject: Re: [PIC]: Dallas DS1305
> > >
> > >I've got some SPI bit-banged code for the Dallas DS1305 RTC on a
> PIC16F877.
> > >If you're interested let me know and I'll post it to the list.
> > >        Sam....
> >
> > e-mail from the desk of John Sanderson, JS Controls.
> > Snailmail:          PO Box 1887, Boksburg 1460, Rep. of South Africa.
> > Tel/fax:            Johannesburg  893 4154
> > Cellphone no:   082 741 6275
> > email:                jsand@pixie.co.za
> > Manufacturer & purveyor of laboratory force testing apparatus, and related
> > products and services.
> >
> > --
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> > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
> >
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> >
> >
> >
>
> --
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