IC Question
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Posts: 46,084
How much flexibility is there in "require about 40 different on/off
buttons". Do you _need_ 40 physical switches that can be immediately
turned on/off? How about 20 switches, each of which can have two
functions depending on some other condition (like the upper and lower
case meanings of the keys on your keyboard, depending on the CAP/CAP
LOCK key). How about 5 switches with eight functions each?
Or, can you use a x*y switch matrix arrangement, where you get x*y
switches with x+y pins? Are the switches simply sending a high or
low to an I/O pin, or switching a load, or...?
If you can have 40 "virtual" switches implemented in a smaller
number of physical switches/pins, you can do the job in software
instead of lots of hardware.
Steve
On 31 Aug 00 at 22:31, mcmgamer@n... wrote:
> Does anyone know the best way to expand the I/O ports of a basic
> stamp IIsx. I am starting a project which will require about 40
> different on/off buttons...
buttons". Do you _need_ 40 physical switches that can be immediately
turned on/off? How about 20 switches, each of which can have two
functions depending on some other condition (like the upper and lower
case meanings of the keys on your keyboard, depending on the CAP/CAP
LOCK key). How about 5 switches with eight functions each?
Or, can you use a x*y switch matrix arrangement, where you get x*y
switches with x+y pins? Are the switches simply sending a high or
low to an I/O pin, or switching a load, or...?
If you can have 40 "virtual" switches implemented in a smaller
number of physical switches/pins, you can do the job in software
instead of lots of hardware.
Steve
On 31 Aug 00 at 22:31, mcmgamer@n... wrote:
> Does anyone know the best way to expand the I/O ports of a basic
> stamp IIsx. I am starting a project which will require about 40
> different on/off buttons...
Comments
stamp IIsx. I am starting a project which will require about 40
different on/off buttons. I found an I/O expander that would work
but it costs $14 for each IC. The way it worked was that it accepted
up to eight different (1 or 0) inputs and combined them into one 8
bit binary number which was then sent to one of the stamps inputs.
Since I would have to buy about 5 or 6 of these IC, it would be
very expensive. Does anyone know of any cheaper ICs that work
similarly? Or, Does anyone have any better suggestions?
P.S. - I am new to microcontrollers. Please keep this in mind when
responding.
THANK YOU!!!
to investigate using a "parallel in, serial out" shift register such as the
Fairchild 74HC165. At around $0.68 each from DigiKey, you could use 5 or 6
of these to each monitor a 'bank' of eight switches with a minimum of I/O
pins being tied up....
Search this List's Archive for 74165 and/or 74hc165 and you will find lots
of helpful info....
Lance.
>
Original Message
> From: mcmgamer@n... [noparse]/noparse]SMTP:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=dBPf-XNQti8gpHETM16_2_9OYM6d039ltnXNz5qeXlX5_nqOO27f6hOj7Yhx2JIetH9amNNs3Ohv6bkIm2Hk]mcmgamer@n...[/url
> Sent: Friday,1 September 2000 9:32
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] IC Question
>
> Does anyone know the best way to expand the I/O ports of a basic
> stamp IIsx. I am starting a project which will require about 40
> different on/off buttons. I found an I/O expander that would work
> but it costs $14 for each IC. The way it worked was that it accepted
> up to eight different (1 or 0) inputs and combined them into one 8
> bit binary number which was then sent to one of the stamps inputs.
> Since I would have to buy about 5 or 6 of these IC, it would be
> very expensive. Does anyone know of any cheaper ICs that work
> similarly? Or, Does anyone have any better suggestions?
>
> P.S. - I am new to microcontrollers. Please keep this in mind when
> responding.
>
> THANK YOU!!!
>
>
>
I was wondering if anyone knew of a website or a way I could look up
the number of an integrated circuit and find out it's use. Thankyou very
much!
Travis
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Stamp stuff. Weather monitoring mostly.
Here is a good chip address:
http://www.hitex.com/chipdir/chipdir.htm
Let us know what you are working on.
Good luck, Kirk
hello,
I was wondering if anyone knew of a website or a way I could look up
the number of an integrated circuit and find out it's use. Thankyou very
much!
Travis
_________________________________________________________________________
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Share information about yourself, create your own public profile at
http://profiles.msn.com.
>hello,
>
> I was wondering if anyone knew of a website or a way I could look up
>the number of an integrated circuit and find out it's use. Thankyou very
>much!
>http://www.hitex.com/chipdir/ and other mirror sites as well. See the first
page of that website for additional information.
> Travis
>_________________________________________________________________________
>Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
>Share information about yourself, create your own public profile at
>http://profiles.msn.com.
> hello,
>
> I was wondering if anyone knew of a website or a way I could look up
> the number of an integrated circuit and find out it's use. Thankyou very
> much!
I was doing this on findchips.com, actually. Found out what a lot of my
supra modem components did.
Just search some parts catalogs.
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"...There's no moral, it's just a lot of stuff that happens". - H. Simpson
www.icmaster.com
mike m
Original Message
From: Travis M <travis_m25@h...>
To: <basicstamps@egroups.com>
Sent: Thursday, November 16, 2000 11:27 AM
Subject: [noparse][[/noparse]basicstamps] IC question
> hello,
>
> I was wondering if anyone knew of a website or a way I could look up
> the number of an integrated circuit and find out it's use. Thankyou very
> much!
>
> Travis
> _________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
> Share information about yourself, create your own public profile at
> http://profiles.msn.com.
>
>
>
>