A Serial Buffer
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Posts: 46,084
Here are the first two paragraphs of a file ("buffer.txt") now
available in the group's file section. Complete description and
programs may be found there.
"Using your Stamp for SERIN operations can be challenging due to its
small buffer size and the need for the SERIN to be active at the
moment the data appear. One solution for these problems is offered
here--a PIC microprocessor programmed as an intelligent serial buffer
that automatically and independently stores up to 1280 bytes of serial
data in volatile RAM for subsequent transfer to your Stamp.
The unique aspect of this solution is that your Stamp (BS2*) can
program the PIC using the program below, which contains both the
programming logic and the embedded PIC program. You run the Stamp's
program only once to produce a programmed PIC ready for ongoing use as
a serial buffer. Cost? About $10 in parts."
Regards,
Steve
available in the group's file section. Complete description and
programs may be found there.
"Using your Stamp for SERIN operations can be challenging due to its
small buffer size and the need for the SERIN to be active at the
moment the data appear. One solution for these problems is offered
here--a PIC microprocessor programmed as an intelligent serial buffer
that automatically and independently stores up to 1280 bytes of serial
data in volatile RAM for subsequent transfer to your Stamp.
The unique aspect of this solution is that your Stamp (BS2*) can
program the PIC using the program below, which contains both the
programming logic and the embedded PIC program. You run the Stamp's
program only once to produce a programmed PIC ready for ongoing use as
a serial buffer. Cost? About $10 in parts."
Regards,
Steve
Comments
The result is a 28-pin narrow DIP (WITH resonator) with a
reprogrammable fixed baud rate, and the price is $7 to $8. The buffer
is huge (1280 bytes), and using the FlowControl pin minimizes the
Stamp's code.
I've been trying to apply the Maxim 3100 (14-pin DIP, WITH crystal
and two caps, SPI interface, but only 8 bytes of buffer, $5.00) to
the same purpose -- with some success -- but only for reciept of
shorter messages.
--- In basicstamps@yahoogroups.com, "S Parkis" <parkiss@e...> wrote:
> Here are the first two paragraphs of a file ("buffer.txt") now
> available in the group's file section. Complete description and
> programs may be found there.
>
> "Using your Stamp for SERIN operations can be challenging due to its
> small buffer size and the need for the SERIN to be active at the
> moment the data appear. One solution for these problems is offered
> here--a PIC microprocessor programmed as an intelligent serial
buffer
> that automatically and independently stores up to 1280 bytes of
serial
> data in volatile RAM for subsequent transfer to your Stamp.
>
> The unique aspect of this solution is that your Stamp (BS2*) can
> program the PIC using the program below, which contains both the
> programming logic and the embedded PIC program. You run the Stamp's
> program only once to produce a programmed PIC ready for ongoing use
as
> a serial buffer. Cost? About $10 in parts."
>
> Regards,
>
> Steve
interrupts for received data on the stamp by programming around it by using
the wait option for the data. This is very inefficient and causes much to
much time being wasted waiting for the data to arrive. Saying that where
can I find this info on the pic and schematic and software. Thanks for this
info my day just got much better
Eric
Original Message
From: "Allan Lane" <allan.lane@h...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, March 24, 2003 11:20 AM
Subject: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
> Cool application -- Using a Stamp to program a PIC Flash on-the-fly.
> The result is a 28-pin narrow DIP (WITH resonator) with a
> reprogrammable fixed baud rate, and the price is $7 to $8. The buffer
> is huge (1280 bytes), and using the FlowControl pin minimizes the
> Stamp's code.
>
> I've been trying to apply the Maxim 3100 (14-pin DIP, WITH crystal
> and two caps, SPI interface, but only 8 bytes of buffer, $5.00) to
> the same purpose -- with some success -- but only for reciept of
> shorter messages.
>
> --- In basicstamps@yahoogroups.com, "S Parkis" <parkiss@e...> wrote:
> > Here are the first two paragraphs of a file ("buffer.txt") now
> > available in the group's file section. Complete description and
> > programs may be found there.
> >
> > "Using your Stamp for SERIN operations can be challenging due to its
> > small buffer size and the need for the SERIN to be active at the
> > moment the data appear. One solution for these problems is offered
> > here--a PIC microprocessor programmed as an intelligent serial
> buffer
> > that automatically and independently stores up to 1280 bytes of
> serial
> > data in volatile RAM for subsequent transfer to your Stamp.
> >
> > The unique aspect of this solution is that your Stamp (BS2*) can
> > program the PIC using the program below, which contains both the
> > programming logic and the embedded PIC program. You run the Stamp's
> > program only once to produce a programmed PIC ready for ongoing use
> as
> > a serial buffer. Cost? About $10 in parts."
> >
> > Regards,
> >
> > Steve
>
>
> To UNSUBSCRIBE, just send mail to:
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Body of the message will be ignored.
>
>
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>
>
>
I too agree, what a awesome solution. I too have been working around the
problem of waiting for a serial input string (even using two stamps, one as
a buffer). This will be very helpful. I too would like more info on the
pic and schematic. I haven't had the change to dive into the PIC world,
yet, so I am not proficient on what is required for resonator, etc.
Thanks again, Dan
This sounds like a great idea.!!! I have been fighting the lack of
interrupts for received data on the stamp by programming around it by using
the wait option for the data. This is very inefficient and causes much to
much time being wasted waiting for the data to arrive. Saying that where
can I find this info on the pic and schematic and software. Thanks for
this
info my day just got much better
Eric
Original Message
From: "Allan Lane" <allan.lane@h...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, March 24, 2003 11:20 AM
Subject: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
> Cool application -- Using a Stamp to program a PIC Flash on-the-fly.
> The result is a 28-pin narrow DIP (WITH resonator) with a
> reprogrammable fixed baud rate, and the price is $7 to $8. The buffer
> is huge (1280 bytes), and using the FlowControl pin minimizes the
> Stamp's code.
>
> I've been trying to apply the Maxim 3100 (14-pin DIP, WITH crystal
> and two caps, SPI interface, but only 8 bytes of buffer, $5.00) to
> the same purpose -- with some success -- but only for reciept of
> shorter messages.
>
> --- In basicstamps@yahoogroups.com, "S Parkis" <parkiss@e...> wrote:
> > Here are the first two paragraphs of a file ("buffer.txt") now
> > available in the group's file section. Complete description and
> > programs may be found there.
> >
http://groups.yahoo.com/group/basicstamps/files/buffer.txt
If there are specific questions not addressed in the above please
ask away. The file at that URL will be updated as typo's and goofs
are found.
The following are at: http://www.phanderson.com/ordering_1.html
- PIC18F252-I/SP, Flash, $6.95
- 4.0 MHz Ceramic Resonator (ECS) with Internal Caps, 3-terminal
SIP, $0.75
Looks like the Good Professor may be on Spring Break for the next
week or so. Parallax also sells the resonator (good picture):
http://www.parallax.com/detail.asp?product_id=250-04050
Digikey, Allied, and Future/Active appear to also have the PIC in
stock.
Regards,
Steve
Eric
Original Message
From: "S Parkis" <parkiss@e...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, March 24, 2003 8:36 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
> The buffer is detailed here (programming, wiring, operation):
>
> http://groups.yahoo.com/group/basicstamps/files/buffer.txt
>
> If there are specific questions not addressed in the above please
> ask away. The file at that URL will be updated as typo's and goofs
> are found.
>
> The following are at: http://www.phanderson.com/ordering_1.html
>
> - PIC18F252-I/SP, Flash, $6.95
>
> - 4.0 MHz Ceramic Resonator (ECS) with Internal Caps, 3-terminal
> SIP, $0.75
>
> Looks like the Good Professor may be on Spring Break for the next
> week or so. Parallax also sells the resonator (good picture):
>
> http://www.parallax.com/detail.asp?product_id=250-04050
>
> Digikey, Allied, and Future/Active appear to also have the PIC in
> stock.
>
> Regards,
>
> Steve
>
> 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/
>
>
If we're interested to let you now. All I can say is GREAT JOB (yes I'm
shouting) keep em coming.
Original Message
From: Eric Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XUlxrFIOpNFbmYhldnIUuf0VN8RrF86oM451rhLYe-bHOoYBBGeCavmvGQijBroKmRd4cwQAOHmSy1OgjIpkg6o]hugs102@b...[/url
Sent: Tuesday, March 25, 2003 1:38 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
Thanks Steve !! As I said you made my day!!!
Eric
Original Message
From: "S Parkis" <parkiss@e...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, March 24, 2003 8:36 PM
Subject: Re: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
> The buffer is detailed here (programming, wiring, operation):
>
> http://groups.yahoo.com/group/basicstamps/files/buffer.txt
>
> If there are specific questions not addressed in the above please
> ask away. The file at that URL will be updated as typo's and goofs
> are found.
>
> The following are at: http://www.phanderson.com/ordering_1.html
>
> - PIC18F252-I/SP, Flash, $6.95
>
> - 4.0 MHz Ceramic Resonator (ECS) with Internal Caps, 3-terminal
> SIP, $0.75
>
> Looks like the Good Professor may be on Spring Break for the next
> week or so. Parallax also sells the resonator (good picture):
>
> http://www.parallax.com/detail.asp?product_id=250-04050
>
> Digikey, Allied, and Future/Active appear to also have the PIC in
> stock.
>
> Regards,
>
> Steve
>
> 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/
[noparse][[/noparse]Non-text portions of this message have been removed]
Heinz Schwenk Germany
Original Message
From: "Sadler Porter" <porter.sadler@s...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, March 26, 2003 3:37 PM
Subject: RE: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
> Steve at the bottom you say there are other solutions the stamp can
program.
> If we're interested to let you now. All I can say is GREAT JOB (yes I'm
> shouting) keep em coming.
>
>
Original Message
> From: Eric Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=BDxPRk2yIMxPLxEMTNPdTVkbQo9a-TyIjiqPdaDOMe7hT_vUHlXKv-Hr0APqJ8BYljzqInvcZyQBlgbjhT2e]hugs102@b...[/url
> Sent: Tuesday, March 25, 2003 1:38 AM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
>
> Thanks Steve !! As I said you made my day!!!
>
> Eric
>
Original Message
> From: "S Parkis" <parkiss@e...>
> To: <basicstamps@yahoogroups.com>
> Sent: Monday, March 24, 2003 8:36 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Re: A Serial Buffer
>
>
> > The buffer is detailed here (programming, wiring, operation):
> >
> > http://groups.yahoo.com/group/basicstamps/files/buffer.txt
> >
> > If there are specific questions not addressed in the above please
> > ask away. The file at that URL will be updated as typo's and goofs
> > are found.
> >
> > The following are at: http://www.phanderson.com/ordering_1.html
> >
> > - PIC18F252-I/SP, Flash, $6.95
> >
> > - 4.0 MHz Ceramic Resonator (ECS) with Internal Caps, 3-terminal
> > SIP, $0.75
> >
> > Looks like the Good Professor may be on Spring Break for the next
> > week or so. Parallax also sells the resonator (good picture):
> >
> > http://www.parallax.com/detail.asp?product_id=250-04050
> >
> > Digikey, Allied, and Future/Active appear to also have the PIC in
> > stock.
> >
> > Regards,
> >
> > Steve
> >
> > 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/
>
>
>
> [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/
>
>
A few questions on the buffer:
-Buffer pin 18 is connected to the outside world as the serial in
point to the PIC. This point is also connected to the stamp at pin 17
(I/O 12).
In the example for the GPS there is a serial out command from the
stamp.
Is this command just inputting a start character for the buffer and
has nothing to do with the GPS??
What happens when the GPS and the Stamp are talking on the same line
at the same time??
Am I missing something??
Thanks
Brent
--- In basicstamps@yahoogroups.com, "S Parkis" <parkiss@e...> wrote:
> The buffer is detailed here (programming, wiring, operation):
>
> http://groups.yahoo.com/group/basicstamps/files/buffer.txt
>
> If there are specific questions not addressed in the above please
> ask away. The file at that URL will be updated as typo's and goofs
> are found.
>
> The following are at: http://www.phanderson.com/ordering_1.html
>
> - PIC18F252-I/SP, Flash, $6.95
>
> - 4.0 MHz Ceramic Resonator (ECS) with Internal Caps, 3-terminal
> SIP, $0.75
>
> Looks like the Good Professor may be on Spring Break for the next
> week or so. Parallax also sells the resonator (good picture):
>
> http://www.parallax.com/detail.asp?product_id=250-04050
>
> Digikey, Allied, and Future/Active appear to also have the PIC in
> stock.
>
> Regards,
>
> Steve
I meant to describe two distinct processes: programming the PIC, and
using a programmed PIC for a real application.
> -Buffer pin 18 is connected to the outside world as the serial in
> point to the PIC. This point is also connected to the stamp at pin
> 17 (I/O 12).
Correct--for the PIC programming operation only. This allows the
Stamp to SEROUT some text into the buffer at the conclusion of
programming the PIC so that the text can be read back to confirm
buffer operation. This isn't actually required to program the PIC,
it just gives you a quick indication that the programming was
successful. For subsequent, operational use of the buffer, the
actual serial data source would be connected to buffer pin 18
instead. The Stamp pin 17 <--> buffer pin 18 connection would not
normally be there except during the one-time PIC programming step.
> In the example for the GPS there is a serial out command from the
> stamp. Is this command just inputting a start character for the
> buffer and has nothing to do with the GPS?? What happens when the
> GPS and the Stamp are talking on the same line at the same time??
> Am I missing something??
You are correct that serial output from the Stamp and the GPS/other
serial device should never both be connected to the buffer's serial
input pin. The GPS demo program shown assumes the PIC has already
been programmed and is ready for use. The SEROUT sends a valid
serial command from Stamp I/O 12 directly to the serial input pin on
the GPS itself, not to buffer pin 18. Output from the GPS is
connected to buffer pin 18.
I hope that helps clear it up.
Regards,
Steve