In a message dated 11/21/2003 6:29:23 PM Eastern Standard Time, forbigmen@a... writes:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
>
If you just want extra output pins, you use a 74HC595 serial shift register.
This takes four I/O lines but will give you eight outputs. By daisy-chaining
another 595 and using one more I/O line, you can get 16 outputs with five I/O
lines.
Sid Weaver
W4EKQ
Port Richey, FL
[noparse][[/noparse]Non-text portions of this message have been removed]
could somebody give me a solution to create extra I/O pins for my
BS2 ?
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I've used Analog multiplexers, Texas instruments CD4067BE. It's a 16
channel MUX that basically is a digitally controlled rotary switch.
You can connect 16 devices to 1 Stamp pin. You give up four Stamp
pins to control the switch position, but get 16 in return. They also
make an 8 channel MUX which requires only 3 I/O. These MUXes don't
work well though with serially controlled devices. There is also
an "on state" resistance associated with the device that you need to
be aware of if your connecting a bunch of RC timing networks (pseudo
analog interface), it's not insignificant for purposes of determining
the time constant. But it works well. Back when I was using RCTIME
for analog input I was running 9 analog inputs into one Stamp pin.
Since then I've pretty much dropped those and gone A to D for inputs
anyway. My favorite is the MAX186 from Maxim. 8 channels of 12 bit
A/D and only requires 3 I/O to control. Despite the name, it's not
just for analog signals, you can sample digital devices with it also.
As others have mentioned you can daisy chain these devices together
and use the enable lines to select which one you want, dramatically
increasing your I/O. Best of luck.
-Dave
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
Another option is to use a shift register, like a 74hc595, or for input and
output expansion a 74ls299. The parallax websight has code and hook up examples
using the 74hc595.
ken
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
[noparse][[/noparse]Non-text portions of this message have been removed]
the easy way that I have found to connect many Inputs / Outputs to
the BS2 is with the PCF8574(A) 8 bit I/O expander from Texas
Instrument. This little device is controlled by using the I2C bus so
it only uses 2 IO pins on the BS2. It is possible to daisy chain 16
chips together for a total of 128 I/O lines using only 2 I/O on the
BS2. NOTE: that will be using (8) PCF8574 and (8) PCF8574A. each bit
is individually programmable and latched at the output.
This is what I am currently using to control 8 CFL outdoor lights
around my house. The BS2 interfaces with 8 25 amp SSR. (I know
overkill but they were free) The PCF8574 has high current outputs,
total of 100ma, plenty to directly drive LEDS, SSR, etc. of course if
you need more current drive you can always tie in (8) 2N2222 NPN's
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
To increase Digital I/O on the BS2, concider using the PCF8574 or
the PCF8574A or their equivalents. The first part is a standard 8-bit
'quasi-bidirectional' I/O that is address settable. The second part is
the same as the first, except that you can connect 16 devices with
software and hardware addressing. The PCF8574 can only have a maximum
of 8 parts connected to the I2C bus. Both parts are I2C bus
architecture. In theory you can have up to 64 I/O lines with the
PCF8574 or 128 I/O lines with the PCF8574A. Both parts are available
in a through-hole DIP package, SOIC (16-pin) or SSOP20 (20-pin)SMT.
The I2C protocols can be found for using the BS2, BS2e or BS2sx with
software. But the BS2p24, BS2p40 or BS2pe have a built in protocol for
using an I2C part (I2CIN and I2COUT).
For more information on this, refer to the following websites: http://www.parallax.com/ http://www.emesystems.com/BS2links.htm http://www.phanderson.com/stamp/ http://focus.ti.com/docs/prod/folders/print/pcf8574.html http://focus.ti.com/docs/prod/folders/print/pcf8574a.html http://www.semiconductors.philips.com/pip/PCF8574T.html
I am currently attempting to work with the PCF8574 using a BS2pe
for a large-scale datalogging project. So as I go, I may have more
information. I am using the PCF8574 to work as address, data and
control registers to interface the BS2pe system to an AMD FLASH memory
device to expand data storage. Any other questions, I will try to
answer them.
Bill, KC9CFO
Another chip to consider is the MCP23016 from Microchip. I find it a
bit easier to use and it has better sink/source ratings than the
PCF8574. For those that are interested I'll post my MCP23016 demo in
the files section.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
To increase Digital I/O on the BS2, concider using the PCF8574 or
the PCF8574A or their equivalents. The first part is a standard 8-bit
'quasi-bidirectional' I/O that is address settable. The second part is
the same as the first, except that you can connect 16 devices with
software and hardware addressing. The PCF8574 can only have a maximum of
8 parts connected to the I2C bus. Both parts are I2C bus architecture.
In theory you can have up to 64 I/O lines with the PCF8574 or 128 I/O
lines with the PCF8574A. Both parts are available in a through-hole DIP
package, SOIC (16-pin) or SSOP20 (20-pin)SMT. The I2C protocols can be
found for using the BS2, BS2e or BS2sx with software. But the BS2p24,
BS2p40 or BS2pe have a built in protocol for using an I2C part (I2CIN
and I2COUT).
For more information on this, refer to the following websites: http://www.parallax.com/http://www.emesystems.com/BS2links.htm http://www.phanderson.com/stamp/ http://focus.ti.com/docs/prod/folders/print/pcf8574.html http://focus.ti.com/docs/prod/folders/print/pcf8574a.html http://www.semiconductors.philips.com/pip/PCF8574T.html
I am currently attempting to work with the PCF8574 using a BS2pe
for a large-scale datalogging project. So as I go, I may have more
information. I am using the PCF8574 to work as address, data and control
registers to interface the BS2pe system to an AMD FLASH memory device to
expand data storage. Any other questions, I will try to answer them.
Bill, KC9CFO
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.
Archiver
Posts: 46,084
Comments
Use SHIFTIN/SHIFTOUT for getting/outputting data.
You can also use the 'p40, it has more I/O pins.
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
forbigmen@a... writes:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
>
If you just want extra output pins, you use a 74HC595 serial shift register.
This takes four I/O lines but will give you eight outputs. By daisy-chaining
another 595 and using one more I/O line, you can get 16 outputs with five I/O
lines.
Sid Weaver
W4EKQ
Port Richey, FL
[noparse][[/noparse]Non-text portions of this message have been removed]
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
Original Message
From: Martial [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=YSIql9jpRdyH3gUnhB_Dq7xztPwWlundfSguY36nDzP-6RL65X8-_LBbPreTwoy_FJ_eSNwS3uAvSsfx]forbigmen@a...[/url
Sent: Friday, November 21, 2003 4:30 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] how to increase BS2 I/O pins?
could somebody give me a solution to create extra I/O pins for my
BS2 ?
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject
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This message has been scanned by WebShield. Please report SPAM to
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channel MUX that basically is a digitally controlled rotary switch.
You can connect 16 devices to 1 Stamp pin. You give up four Stamp
pins to control the switch position, but get 16 in return. They also
make an 8 channel MUX which requires only 3 I/O. These MUXes don't
work well though with serially controlled devices. There is also
an "on state" resistance associated with the device that you need to
be aware of if your connecting a bunch of RC timing networks (pseudo
analog interface), it's not insignificant for purposes of determining
the time constant. But it works well. Back when I was using RCTIME
for analog input I was running 9 analog inputs into one Stamp pin.
Since then I've pretty much dropped those and gone A to D for inputs
anyway. My favorite is the MAX186 from Maxim. 8 channels of 12 bit
A/D and only requires 3 I/O to control. Despite the name, it's not
just for analog signals, you can sample digital devices with it also.
As others have mentioned you can daisy chain these devices together
and use the enable lines to select which one you want, dramatically
increasing your I/O. Best of luck.
-Dave
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
output expansion a 74ls299. The parallax websight has code and hook up examples
using the 74hc595.
ken
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
[noparse][[/noparse]Non-text portions of this message have been removed]
the BS2 is with the PCF8574(A) 8 bit I/O expander from Texas
Instrument. This little device is controlled by using the I2C bus so
it only uses 2 IO pins on the BS2. It is possible to daisy chain 16
chips together for a total of 128 I/O lines using only 2 I/O on the
BS2. NOTE: that will be using (8) PCF8574 and (8) PCF8574A. each bit
is individually programmable and latched at the output.
This is what I am currently using to control 8 CFL outdoor lights
around my house. The BS2 interfaces with 8 25 amp SSR. (I know
overkill but they were free) The PCF8574 has high current outputs,
total of 100ma, plenty to directly drive LEDS, SSR, etc. of course if
you need more current drive you can always tie in (8) 2N2222 NPN's
This chip, PCF8574, is available from www.digikey.com for only $2
http://www.digikey.com/scripts/us/dksus.dll?Detail?Ref=117374&Row=50850
The datasheet can be found at
http://www.digikey.com/scripts/us/dksus.dll?Detail?Ref=117374&Row=50850
Daryl
At 06:51 PM 11/21/2003, you 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
>
>
>
Original Message
>From: Martial [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ZRAufsIOnaUfZQkpBd0i9xRPPTYKHxbd6w8cgB2B-VgOGI8J5XMIouM8ltA7SW6N9nggTb3DCOsR]forbigmen@a...[/url
>Sent: Friday, November 21, 2003 4:30 PM
>To: basicstamps@yahoogroups.com
>Subject: [noparse][[/noparse]basicstamps] how to increase BS2 I/O pins?
>
>
>could somebody give me a solution to create extra I/O pins for my
>BS2 ?
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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>and Body of the message will be ignored.
>
>
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>http://docs.yahoo.com/info/terms/
>
>
>
>
>This message has been scanned by WebShield. Please report SPAM to
>abuse@p....
>
>
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>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
To increase Digital I/O on the BS2, concider using the PCF8574 or
the PCF8574A or their equivalents. The first part is a standard 8-bit
'quasi-bidirectional' I/O that is address settable. The second part is
the same as the first, except that you can connect 16 devices with
software and hardware addressing. The PCF8574 can only have a maximum
of 8 parts connected to the I2C bus. Both parts are I2C bus
architecture. In theory you can have up to 64 I/O lines with the
PCF8574 or 128 I/O lines with the PCF8574A. Both parts are available
in a through-hole DIP package, SOIC (16-pin) or SSOP20 (20-pin)SMT.
The I2C protocols can be found for using the BS2, BS2e or BS2sx with
software. But the BS2p24, BS2p40 or BS2pe have a built in protocol for
using an I2C part (I2CIN and I2COUT).
For more information on this, refer to the following websites:
http://www.parallax.com/
http://www.emesystems.com/BS2links.htm
http://www.phanderson.com/stamp/
http://focus.ti.com/docs/prod/folders/print/pcf8574.html
http://focus.ti.com/docs/prod/folders/print/pcf8574a.html
http://www.semiconductors.philips.com/pip/PCF8574T.html
I am currently attempting to work with the PCF8574 using a BS2pe
for a large-scale datalogging project. So as I go, I may have more
information. I am using the PCF8574 to work as address, data and
control registers to interface the BS2pe system to an AMD FLASH memory
device to expand data storage. Any other questions, I will try to
answer them.
Bill, KC9CFO
bit easier to use and it has better sink/source ratings than the
PCF8574. For those that are interested I'll post my MCP23016 demo in
the files section.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: wschini03 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=JZPtsuW206vmo5FJlo69pyYAkvn27guT0TVWneO46QCu6yPvJZ7F3_x3eXzafBEDHs8H4D1KIo6T5gMXcfw]wschini03@y...[/url
Sent: Tuesday, December 02, 2003 2:53 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: how to increase BS2 I/O pins?
--- In basicstamps@yahoogroups.com, "Martial" <forbigmen@a...> wrote:
> could somebody give me a solution to create extra I/O pins for my
> BS2 ?
To increase Digital I/O on the BS2, concider using the PCF8574 or
the PCF8574A or their equivalents. The first part is a standard 8-bit
'quasi-bidirectional' I/O that is address settable. The second part is
the same as the first, except that you can connect 16 devices with
software and hardware addressing. The PCF8574 can only have a maximum of
8 parts connected to the I2C bus. Both parts are I2C bus architecture.
In theory you can have up to 64 I/O lines with the PCF8574 or 128 I/O
lines with the PCF8574A. Both parts are available in a through-hole DIP
package, SOIC (16-pin) or SSOP20 (20-pin)SMT. The I2C protocols can be
found for using the BS2, BS2e or BS2sx with software. But the BS2p24,
BS2p40 or BS2pe have a built in protocol for using an I2C part (I2CIN
and I2COUT).
For more information on this, refer to the following websites:
http://www.parallax.com/ http://www.emesystems.com/BS2links.htm
http://www.phanderson.com/stamp/
http://focus.ti.com/docs/prod/folders/print/pcf8574.html
http://focus.ti.com/docs/prod/folders/print/pcf8574a.html
http://www.semiconductors.philips.com/pip/PCF8574T.html
I am currently attempting to work with the PCF8574 using a BS2pe
for a large-scale datalogging project. So as I go, I may have more
information. I am using the PCF8574 to work as address, data and control
registers to interface the BS2pe system to an AMD FLASH memory device to
expand data storage. Any other questions, I will try to answer them.
Bill, KC9CFO
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
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This message has been scanned by WebShield. Please report SPAM to
abuse@p....