how to increase BS2 I/O pins? 74HC165 for multiple inputs
Archiver
Posts: 46,084
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> Outputs... 74HC595
> Inputs.... 74HC165
> Mixed..... PCF8574 (I2C)
>
> These are all simple, inexpesive devices and you can find source
code
> for each on our web site.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
I hate to take the lazy way out (but only slightly)
does the 74HC165 need to be polled to see the status or does it
generate a signal that a switch has changed ?
I will read the data sheets this week, but up to my elbos with work
for the short work week.
Dave
wrote:
> Outputs... 74HC595
> Inputs.... 74HC165
> Mixed..... PCF8574 (I2C)
>
> These are all simple, inexpesive devices and you can find source
code
> for each on our web site.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
I hate to take the lazy way out (but only slightly)
does the 74HC165 need to be polled to see the status or does it
generate a signal that a switch has changed ?
I will read the data sheets this week, but up to my elbos with work
for the short work week.
Dave
Comments
The 74HC165 doesn't have any "smarts" -- you have to poll it by shifting the
state of its pins into your Stamp. They're called "shift registers" and this
one converts 8 bits of parallel data into serial, allowing the Stamp to read
it with only a few I/O pins.
Randy
www.glitchbuster.com
Original Message
From: "Dave Mucha" <davemucha@j...>
To: <basicstamps@yahoogroups.com>
Sent: Sunday, November 23, 2003 7:54 PM
Subject: [noparse][[/noparse]basicstamps] Re: how to increase BS2 I/O pins? 74HC165 for
multiple inputs
> --- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
> wrote:
> > Outputs... 74HC595
> > Inputs.... 74HC165
> > Mixed..... PCF8574 (I2C)
> >
> > These are all simple, inexpesive devices and you can find source
> code
> > for each on our web site.
> >
> > -- Jon Williams
> > -- Applications Engineer, Parallax
> > -- Dallas Office
>
>
> I hate to take the lazy way out (but only slightly)
>
> does the 74HC165 need to be polled to see the status or does it
> generate a signal that a switch has changed ?
>
> I will read the data sheets this week, but up to my elbos with work
> for the short work week.
>
> Dave
>
>
>
>
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