portssss !!!!!!!!
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Posts: 46,084
I'm new with BASIC Stamp....I want to increase the number of the
ports becasue my application need more than 15 ports ????
ports becasue my application need more than 15 ports ????
Comments
rak_eyes83@y... writes:
> I'm new with BASIC Stamp....I want to increase the number of the
> ports becasue my application need more than 15 ports ????
>
>
How you increase the number of ports depends on your application. If you
just need On-Off the a 595 shift register will work. If you need to switch
power
then a TPIC9595 would work. Both chips take 3 lines - you get 8 outputs for
3 inputs. If you daisy chain them you get 16 for 4 lines, 24 for 5 lines and
so on.
Sid Weaver
W4EKQ
Port Richey, FL
[noparse][[/noparse]Non-text portions of this message have been removed]
people use shift registers or multiplexers/demultiplexers to add simple I/O
to the Stamp. In addition, many of our PAKs add features including extra
I/O. One thing nice about a PAK-IV, for example, is that it adds 16 pins
(and takes away 2), but you can do certain things concurrently. For example,
you can command the PAK to make, say, 500mS of pulses on one output and then
have the Stamp do something else on one of its pins at the same time. You
can't easily do that with a BS2P/40 or shift registers.
Hope that helps.
Al Williams
AWC
http://www.awce.com/pak3.htm
Original Message
From: rak_eyes83 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XUdQaFbwqB8-3iNWvF2lFUodRS5t98xZv08LSb3ZEG_rFenFp1SWVRDfXmbqeQr3jkGCpnPPe3KvqECM]rak_eyes83@y...[/url
Sent: Saturday, April 03, 2004 6:23 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] portssss !!!!!!!!
I'm new with BASIC Stamp....I want to increase the number of the
ports becasue my application need more than 15 ports ????
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output ports, strickly input ports or need to do both?
If strictly output ports, an easy solution is to use a 74HC595 serial shift
register. If strictly imputs, use a 74HC165. To use one of these, all the work
has already been done!!!!! At the Parallax websight examples are given. Here
is the link:
http://www.parallax.com/html_pages/downloads/sw/sw.asp
See stampworks experiments 23, 23b, 24, and 24b
If you need to do both with one IC, you can use a 74LS299 serial shift
register. There is no code on the parallax sight for one of these, but I have
code I
could share if needed.
ken
I'm new with BASIC Stamp....I want to increase the number of the
ports becasue my application need more than 15 ports ????
[noparse][[/noparse]Non-text portions of this message have been removed]
Outputs.... 74HC595 (SPI part)
Inputs..... 74HC165 (SPI part)
Mixed IO... MCP23016 (I2C part)
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: rak_eyes83 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=tMOf6-mz-jzivhAaZDlFwTBBbDdi8vOMM4gCwrAZipHzPZAWjfefK1nq0NyNe9zCwOTDndDrA-kZw44p]rak_eyes83@y...[/url
Sent: Saturday, April 03, 2004 6:23 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] portssss !!!!!!!!
I'm new with BASIC Stamp....I want to increase the number of the
ports becasue my application need more than 15 ports ????
wrote:
> I'm new with BASIC Stamp....I want to increase the number of the
> ports becasue my application need more than 15 ports ????
Another option is if you need ADC, an 11 channel, serial ADC can be
used for both digital and serial with a little software. That would
use a couple pins but offer half of your needed additional lines.
Dave
> If you daisy chain [noparse][[/noparse]the '595s] you get 16 [noparse][[/noparse]outputs] for 4 lines,
> 24 for 5 lines and so on.
At some point, it probably makes more sense to drive the shift
register portions of the '595s in parallel and selectively clock the
storage register of the one that you want to update using a decoder.
For example, using 3 pins to drive a '138, and one to strobe it plus
the data and clock lines makes 6 I/O pins to get 64 outputs. The
general formula for that structure is (2^(N - 3))*8 outputs for N
inputs (N>=3).
The method you describe produces (N-2)*8 outputs for N inputs
(N>=2). The two methods produce the same number of outputs for N=3
(no decoder required). After that, using a decoder produces more
outputs at the expense of using an extra chip.