32 Input via paralel port ?
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Hi helpers,
I have no more idea where to surch.
What IC could I use ?
I would like to connect 32 inputs (high=12V) via
paralel port to the Stamp.
I think via paralel is the best, because I have
only very short time to read und controle the inputs.
Can someone tell me where to surch, or which IC
I may use?
Thanks Heinz Schwenk Germany
I have no more idea where to surch.
What IC could I use ?
I would like to connect 32 inputs (high=12V) via
paralel port to the Stamp.
I think via paralel is the best, because I have
only very short time to read und controle the inputs.
Can someone tell me where to surch, or which IC
I may use?
Thanks Heinz Schwenk Germany
Comments
hschwenk@g... writes:
> Hi helpers,
> I have no more idea where to surch.
> What IC could I use ?
> I would like to connect 32 inputs (high=12V) via
> paralel port to the Stamp.
> I think via paralel is the best, because I have
> only very short time to read und controle the inputs.
> Can someone tell me where to surch, or which IC
> I may use?
>
> Thanks Heinz Schwenk Germany
How much time do you have to "read & react"? The first thing that comes to
mind is a serial shift register,
The 12 v high can easily be tranlated to TTL with opto isolators or simple
2n4904 transistors.....
Little more detail on "time " to read & react.......
[noparse][[/noparse]Non-text portions of this message have been removed]
Thanks for Your quick replay
I use a BS2P 40
I count the revolution (2 channel) of 4 gear motors
And between the counts I have to check a lot of switches
and to react. For every think I have about 8 msec
A shift register needs also some code and the stamp needs time
I was looking for something like
a quick keypad encoder with parallel out
or two Cmos encoder 16 in and 4 parallel out.
The 12 V, I thought to handle with the cmos IC,
or with a divider 2 resistor, or a zehnerdiod ?
But don't find the "good" IC ..?
best regards Heinz
Original Message
From: <smartdim@a...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, June 13, 2003 3:26 AM
Subject: Re: [noparse][[/noparse]basicstamps] 32 Input via paralel port ?
> In a message dated 6/12/2003 4:46:06 PM Pacific Daylight Time,
> hschwenk@g... writes:
>
> > Hi helpers,
> > I have no more idea where to surch.
> > What IC could I use ?
> > I would like to connect 32 inputs (high=12V) via
> > paralel port to the Stamp.
> > I think via paralel is the best, because I have
> > only very short time to read und controle the inputs.
> > Can someone tell me where to surch, or which IC
> > I may use?
> >
> > Thanks Heinz Schwenk Germany
>
> How much time do you have to "read & react"? The first thing that comes
to
> mind is a serial shift register,
>
> The 12 v high can easily be tranlated to TTL with opto isolators or simple
> 2n4904 transistors.....
>
> Little more detail on "time " to read & react.......
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
24 parallel in/out signals per chip.
A 74x164 Par to Ser (let's see, 16 KBit/Sec SHIFIN,
32 inputs == 4 chips, that's 2 mSec for all
32 bits -- oops, that's a little tight...)
74HCT373 is a Par to Par latch. 8 data bits, a
chip select, and an output enable is all you need,
and the data bits can be common.
The 12 volts can be a problem though...
--- In basicstamps@yahoogroups.com, "HSchwenk_GMX" <hschwenk@g...>
wrote:
> Hi helpers,
> I have no more idea where to surch.
> What IC could I use ?
> I would like to connect 32 inputs (high=12V) via
> paralel port to the Stamp.
> I think via paralel is the best, because I have
> only very short time to read und controle the inputs.
> Can someone tell me where to surch, or which IC
> I may use?
>
> Thanks Heinz Schwenk Germany
There are such ICs, and I think what you are looking for is usually
called a "priority encoder", such as the cmos CD4532. That one has 8
inputs and 3 main outputs, and the outputs show the binary state of
the inputs. There are a couple of auxiliary outputs that allow you
distinguish the input 0 from nothing-pressed, and to cascade devices
to get more inputs. It is called priority, because if two inputs are
pressed at once, it is the highest one that determines the output
state. These things were commonly used in interrupt logic
controllers.
That said, the shift register may still be a better option with the
Stamp. On the BS2P the actual shiftin command to read in 32 inputs
into 4 bytes would take less than one millisecond. Then you have the
state of all the pins at your disposal to work with, in case two
happen to be pressed at once. That is within the 8 milliseconds you
have available and is probably not much different from the time it
would take for the PBASIC interpreter to read in the state of a
parallel encoder.
-- best regards
Tracy Allen
electronically monitored ecosystems
http://www.emesystems.com
mailto:tracy@e...
>Hi
>Thanks for Your quick replay
>I use a BS2P 40
>I count the revolution (2 channel) of 4 gear motors
>And between the counts I have to check a lot of switches
>and to react. For every think I have about 8 msec
>A shift register needs also some code and the stamp needs time
>I was looking for something like
>a quick keypad encoder with parallel out
>or two Cmos encoder 16 in and 4 parallel out.
>The 12 V, I thought to handle with the cmos IC,
>or with a divider 2 resistor, or a zehnerdiod ?
>But don't find the "good" IC ..?
>
>best regards Heinz
>
>
>
>
Original Message
>From: <smartdim@a...>
>To: <basicstamps@yahoogroups.com>
>Sent: Friday, June 13, 2003 3:26 AM
>Subject: Re: [noparse][[/noparse]basicstamps] 32 Input via paralel port ?
>
>
>> In a message dated 6/12/2003 4:46:06 PM Pacific Daylight Time,
>> hschwenk@g... writes:
>>
>> > Hi helpers,
>> > I have no more idea where to surch.
>> > What IC could I use ?
>> > I would like to connect 32 inputs (high=12V) via
>> > paralel port to the Stamp.
>> > I think via paralel is the best, because I have
>> > only very short time to read und controle the inputs.
>> > Can someone tell me where to surch, or which IC
>> > I may use?
>> >
>> > Thanks Heinz Schwenk Germany
>>
>> How much time do you have to "read & react"? The first thing that comes
>to
>> mind is a serial shift register,
>>
>> The 12 v high can easily be tranlated to TTL with opto isolators or simple
>> 2n4904 transistors.....
>>
>> Little more detail on "time " to read & react.......
>>
>>
>> [noparse][[/noparse]Non-text portions of this message have been removed]
>>
>>
>> To UNSUBSCRIBE, just send mail to:
>> basicstamps-unsubscribe@yahoogroups.com
>> from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>>
>>
>> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>>
>>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the
>Subject and Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/