Kerr Pic-Servo Board
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Posts: 46,084
Hello,
I'm new to stamps and could use some advice on how to set up the hardware
for my project before I begin to program. Over the past couple of weeks I
ve enjoyed programming small test programs and have been monitoring this
great list.
I'm wondering if anyone has used the JR Kerr Pic-Servo boards with a basic
stamp? The board interphases using the RS485 serial protocol. It is my
understanding that this is just like RS232 except that it is +5 and 0 volts
instead of +12 and -12 volts, so I'm thinking that there should be no
problem sending and receiving commands with the stamp. Is this correct? JR
Kerr offers a RS485 to RS232 converter board, but I don't think I would need
to use that.
A concern of mine is that the stamps (i'm using the 2p) in the manual are
said to be tricky when receiving serial data at 9600 baud, the lowest
communication rate of the Pic-Servo. Is there a chip that would work as a
serial buffer that could receive serial data from the Pic-Servo at a higher
baud rate, and be read by the stamp at a lower baud rate?
If anyone has used the Pic-Servo I'd appreciate hearing about your
experiences.
On another issue, I need to have six buttons to interphase with my programs
by receiving user input. Design wise, is it better to have six different
pushbuttons connected to six IO pins on the stamp and use the BUTTON command
to look at each button in a loop until one is hit, or would it be better to
use a keypad with a serial interphase (I saw a chip on someones web site
from this list that did this) so I only have to read once to get input from
all the buttons (only one button will be pushed at a time).
Thanks,
Stewart
[noparse][[/noparse]Non-text portions of this message have been removed]
I'm new to stamps and could use some advice on how to set up the hardware
for my project before I begin to program. Over the past couple of weeks I
ve enjoyed programming small test programs and have been monitoring this
great list.
I'm wondering if anyone has used the JR Kerr Pic-Servo boards with a basic
stamp? The board interphases using the RS485 serial protocol. It is my
understanding that this is just like RS232 except that it is +5 and 0 volts
instead of +12 and -12 volts, so I'm thinking that there should be no
problem sending and receiving commands with the stamp. Is this correct? JR
Kerr offers a RS485 to RS232 converter board, but I don't think I would need
to use that.
A concern of mine is that the stamps (i'm using the 2p) in the manual are
said to be tricky when receiving serial data at 9600 baud, the lowest
communication rate of the Pic-Servo. Is there a chip that would work as a
serial buffer that could receive serial data from the Pic-Servo at a higher
baud rate, and be read by the stamp at a lower baud rate?
If anyone has used the Pic-Servo I'd appreciate hearing about your
experiences.
On another issue, I need to have six buttons to interphase with my programs
by receiving user input. Design wise, is it better to have six different
pushbuttons connected to six IO pins on the stamp and use the BUTTON command
to look at each button in a loop until one is hit, or would it be better to
use a keypad with a serial interphase (I saw a chip on someones web site
from this list that did this) so I only have to read once to get input from
all the buttons (only one button will be pushed at a time).
Thanks,
Stewart
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
>understanding that this is just like RS232 except that it is +5 and 0 volts
>instead of +12 and -12 volts, so I'm thinking that there should be no
>problem sending and receiving commands with the stamp.
Hi Stewart,
RS485 is a balanced differential signal with voltages going (+5 to 0)
and (0 to +5) in 180 degree opposition on two lines. There are 8-pin
chips that make the translation from TTL to RS485 and back. You can
kluge it, though, for a short distance run. On input to the stamp,
pick one of the signal lines and ignore the other. That is like
normal 0-5 volt RS232. On output from the stamp, tie one of the
lines that goes to your device to +2.5 volts and output normal RS232
from the other. That fakes the differential signal. It is better of
course to use the real RS485 to benefit from the noise immunity it
provides. The chips are cheap.
>A concern of mine is that the stamps (i'm using the 2p) in the manual are
>said to be tricky when receiving serial data at 9600 baud, the lowest
>communication rate of the Pic-Servo. Is there a chip that would work as a
>serial buffer that could receive serial data from the Pic-Servo at a higher
>baud rate, and be read by the stamp at a lower baud rate?
It really depends on how much data is coming into the stamp at one
time. It is possible to get very good results at 9600 baud, for
example, in a command response system with the Stamp as master. I do
not have experience with the Pic-Servo, though. There _are_ buffer
chips. One is the MAX3100. Another is the DIY serial buffer that Al
outlined in his SX chip programming course.
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
There is a circuit using RCTIME that you can use that will allow
you to use one I/O line to check the state of several switches.
Look in the Stamp1.9 Manual (if you have one) on page 155 and it
gives a sample using POT for a StampI. If you have a Stamp2, or
whatever, you will have to do the conversion as described in the
appendix starting on page 426. If you don't have the Stamp1.9
manual, let me know and I will try to help you with the specifics.
On 16 Sep 2001, at 13:00, Stewart Mayer wrote:
> Hello,
>
> I'm new to stamps and could use some advice on how to set up the
> hardware for my project before I begin to program. Over the past
> couple of weeks I ve enjoyed programming small test programs and have
> been monitoring this great list.
>
> I'm wondering if anyone has used the JR Kerr Pic-Servo boards with a
> basic stamp? The board interphases using the RS485 serial protocol.
> It is my understanding that this is just like RS232 except that it is
> +5 and 0 volts instead of +12 and -12 volts, so I'm thinking that
> there should be no problem sending and receiving commands with the
> stamp. Is this correct? JR Kerr offers a RS485 to RS232 converter
> board, but I don't think I would need to use that.
>
> A concern of mine is that the stamps (i'm using the 2p) in the manual
> are said to be tricky when receiving serial data at 9600 baud, the
> lowest communication rate of the Pic-Servo. Is there a chip that
> would work as a serial buffer that could receive serial data from the
> Pic-Servo at a higher baud rate, and be read by the stamp at a lower
> baud rate?
>
> If anyone has used the Pic-Servo I'd appreciate hearing about your
> experiences.
>
> On another issue, I need to have six buttons to interphase with my
> programs by receiving user input. Design wise, is it better to have
> six different pushbuttons connected to six IO pins on the stamp and
> use the BUTTON command to look at each button in a loop until one is
> hit, or would it be better to use a keypad with a serial interphase (I
> saw a chip on someones web site from this list that did this) so I
> only have to read once to get input from all the buttons (only one
> button will be pushed at a time).
>
> Thanks,
> Stewart
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
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>
it right away.
Regards,
Stewart
Original Message
From: basicstamps@yahoogroups.com
Date: Monday, September 17, 2001 01:50:23 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Kerr Pic-Servo Board
Don't know on the kerr Serial thing, but about the buttons. . .
There is a circuit using RCTIME that you can use that will allow
you to use one I/O line to check the state of several switches.
Look in the Stamp1.9 Manual (if you have one) on page 155 and it
gives a sample using POT for a StampI. If you have a Stamp2, or
whatever, you will have to do the conversion as described in the
appendix starting on page 426. If you don't have the Stamp1.9
manual, let me know and I will try to help you with the specifics.
On 16 Sep 2001, at 13:00, Stewart Mayer wrote:
> Hello,
>
> I'm new to stamps and could use some advice on how to set up the
> hardware for my project before I begin to program. Over the past
> couple of weeks I ve enjoyed programming small test programs and have
> been monitoring this great list.
>
> I'm wondering if anyone has used the JR Kerr Pic-Servo boards with a
> basic stamp? The board interphases using the RS485 serial protocol.
> It is my understanding that this is just like RS232 except that it is
> +5 and 0 volts instead of +12 and -12 volts, so I'm thinking that
> there should be no problem sending and receiving commands with the
> stamp. Is this correct? JR Kerr offers a RS485 to RS232 converter
> board, but I don't think I would need to use that.
>
> A concern of mine is that the stamps (i'm using the 2p) in the manual
> are said to be tricky when receiving serial data at 9600 baud, the
> lowest communication rate of the Pic-Servo. Is there a chip that
> would work as a serial buffer that could receive serial data from the
> Pic-Servo at a higher baud rate, and be read by the stamp at a lower
> baud rate?
>
> If anyone has used the Pic-Servo I'd appreciate hearing about your
> experiences.
>
> On another issue, I need to have six buttons to interphase with my
> programs by receiving user input. Design wise, is it better to have
> six different pushbuttons connected to six IO pins on the stamp and
> use the BUTTON command to look at each button in a loop until one is
> hit, or would it be better to use a keypad with a serial interphase (I
> saw a chip on someones web site from this list that did this) so I
> only have to read once to get input from all the buttons (only one
> button will be pushed at a time).
>
> Thanks,
> Stewart
>
> [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/
[noparse][[/noparse]Non-text portions of this message have been removed]
only have a few feet of cable run, but i'm not quite sure (being a novice)
exactly how to tie the output to +2.5 volts. Will I need another power
regulator to get that ammount of voltage or will a resistor do it? If you
ve got a moment to go into it further I'd appreciate it. Also, I don't mind
spending a few bucks on a chip to do it right, I've looked at the digikey
online catalog but there are so many rs485 related chips that I'm unsure
what to look for specifically.
The JR Kerr servo controllers are realy neet, I've been playing with them
from the test software that comes with them. Check them out at www.jrkerr
com
Regards,
Stewart
Original Message
From: basicstamps@yahoogroups.com
Date: Monday, September 17, 2001 12:30:53 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Kerr Pic-Servo Board
>The board interphases using the RS485 serial protocol. It is my
>understanding that this is just like RS232 except that it is +5 and 0 volts
>instead of +12 and -12 volts, so I'm thinking that there should be no
>problem sending and receiving commands with the stamp.
Hi Stewart,
RS485 is a balanced differential signal with voltages going (+5 to 0)
and (0 to +5) in 180 degree opposition on two lines. There are 8-pin
chips that make the translation from TTL to RS485 and back. You can
kluge it, though, for a short distance run. On input to the stamp,
pick one of the signal lines and ignore the other. That is like
normal 0-5 volt RS232. On output from the stamp, tie one of the
lines that goes to your device to +2.5 volts and output normal RS232
from the other. That fakes the differential signal. It is better of
course to use the real RS485 to benefit from the noise immunity it
provides. The chips are cheap.
>A concern of mine is that the stamps (i'm using the 2p) in the manual are
>said to be tricky when receiving serial data at 9600 baud, the lowest
>communication rate of the Pic-Servo. Is there a chip that would work as a
>serial buffer that could receive serial data from the Pic-Servo at a higher
>baud rate, and be read by the stamp at a lower baud rate?
It really depends on how much data is coming into the stamp at one
time. It is possible to get very good results at 9600 baud, for
example, in a command response system with the Stamp as master. I do
not have experience with the Pic-Servo, though. There _are_ buffer
chips. One is the MAX3100. Another is the DIY serial buffer that Al
outlined in his SX chip programming course.
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
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.
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[noparse][[/noparse]Non-text portions of this message have been removed]
Are we speaking Enlish here or what?
Tracy Allen wrote:
>
> >The board interphases using the RS485 serial protocol. It is my
> >understanding that this is just like RS232 except that it is +5 and 0 volts
> >instead of +12 and -12 volts, so I'm thinking that there should be no
> >problem sending and receiving commands with the stamp.
>
> Hi Stewart,
>
> RS485 is a balanced differential signal with voltages going (+5 to 0)
> and (0 to +5) in 180 degree opposition on two lines. There are 8-pin
> chips that make the translation from TTL to RS485 and back. You can
> kluge it, though, for a short distance run. On input to the stamp,
> pick one of the signal lines and ignore the other. That is like
> normal 0-5 volt RS232. On output from the stamp, tie one of the
> lines that goes to your device to +2.5 volts and output normal RS232
> from the other. That fakes the differential signal. It is better of
> course to use the real RS485 to benefit from the noise immunity it
> provides. The chips are cheap.
>
> >A concern of mine is that the stamps (i'm using the 2p) in the manual are
> >said to be tricky when receiving serial data at 9600 baud, the lowest
> >communication rate of the Pic-Servo. Is there a chip that would work as a
> >serial buffer that could receive serial data from the Pic-Servo at a higher
> >baud rate, and be read by the stamp at a lower baud rate?
>
> It really depends on how much data is coming into the stamp at one
> time. It is possible to get very good results at 9600 baud, for
> example, in a command response system with the Stamp as master. I do
> not have experience with the Pic-Servo, though. There _are_ buffer
> chips. One is the MAX3100. Another is the DIY serial buffer that Al
> outlined in his SX chip programming course.
>
> -- regards,
> Tracy Allen
> electronically monitored ecosystems
> mailto:tracy@e...
> http://www.emesystems.com
>
> 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/