Sort of a newbie...could use some help!?
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Posts: 46,084
Ok guys...I'm working on a project that will interface with a PCF8583
RTC wRam. Here is my problem......I have no idea what I'm doing with
respect to I2C. I really need someone to break this down to basics
for me. I'm specifically looking for an alarm from the RCT every
1/10th of a second. But Like I said...I don't get the I2C protocol.
Any help would be appreciated.
James
Success is 1% inspiration and 99% perspiration. (Thomas Edison)
RTC wRam. Here is my problem......I have no idea what I'm doing with
respect to I2C. I really need someone to break this down to basics
for me. I'm specifically looking for an alarm from the RCT every
1/10th of a second. But Like I said...I don't get the I2C protocol.
Any help would be appreciated.
James
Success is 1% inspiration and 99% perspiration. (Thomas Edison)
Comments
>Ok guys...I'm working on a project that will interface with a PCF8583
>RTC wRam. Here is my problem......I have no idea what I'm doing with
>respect to I2C. I really need someone to break this down to basics
>for me. I'm specifically looking for an alarm from the RCT every
>1/10th of a second. But Like I said...I don't get the I2C protocol.
>
>
>Any help would be appreciated.
>
>
>James
>Success is 1% inspiration and 99% perspiration. (Thomas Edison)
James -
In order to answer your question it would help if we knew what kind of
Stamp you're using, or planning to use.
Bruce Bates
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Philips. The short story is that it is a synchronous (separate data and
clock lines), multi-drop buss. Devices on the buss are addressed by
type and unit (many I2C devices support more than one of the same device
type on the buss).
The BS2p and BS2pe have built-in I2C commands, but you can bit-bang the
signaling using SHIFTOUT and SHIFTIN with other BS2 micros. I've even
heard that some people have written BS1 code for I2C. Now that I can
program my BS1 from Windows (in testing -- you'll get it soon too!) I
will give it a try.
Take a look at our Nuts & Volts material -- you'll find Column #85 "I2C
Fun for Everyone" useful. You'll find it in the Downloads section of
our web site.
If memory serves me, the PCF8583 has a 1 Hz output signal, so for your
project you'll need to poll the 1/100th seconds register and work from
there.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: jelongus [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=LH6OwIiP0F0ISmSJgYHYtTsdy5wJcycw8mPvN20xJtKmSnMAoKOkGlroWrtg0NuJsHg2bWyxQM_MXosGhYX-5pBTdEFq]propellanttech@c...[/url
Sent: Tuesday, October 07, 2003 9:25 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Sort of a newbie...could use some help!?
Ok guys...I'm working on a project that will interface with a PCF8583
RTC wRam. Here is my problem......I have no idea what I'm doing with
respect to I2C. I really need someone to break this down to basics
for me. I'm specifically looking for an alarm from the RCT every
1/10th of a second. But Like I said...I don't get the I2C protocol.
Any help would be appreciated.
James
Success is 1% inspiration and 99% perspiration. (Thomas Edison)
To UNSUBSCRIBE, just send mail to:
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wiring and code. The example pertains specifically to the SRF08 ultrasonic
sensor, but should work with the PCF8583 by substituting the appropriate
device address and functions codes.
-- Al Margolis, founder
www.hobbyengineering.com
The technology builder's source for kits, components, supplies, tools, books
and education.
Original Message
From: jelongus [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=RG0FCkBo5_EYfuQgbDPeRQxX2zXlz6a52lhgSe0EmOK_pZks5B43iomXcpX1N09OOFkYt1Z2twcGg3CNvM9MGzeTkQ]propellanttech@c...[/url
Sent: Tuesday, October 07, 2003 7:25 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Sort of a newbie...could use some help!?
Ok guys...I'm working on a project that will interface with a PCF8583
RTC wRam. Here is my problem......I have no idea what I'm doing with
respect to I2C. I really need someone to break this down to basics
for me. I'm specifically looking for an alarm from the RCT every
1/10th of a second. But Like I said...I don't get the I2C protocol.
Any help would be appreciated.
James
Success is 1% inspiration and 99% perspiration. (Thomas Edison)
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
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I2C for Everyone.
It is a good article by the BS2 guru Mr. Jon Williams.
It should be enough to get you started.
Good luck.
--- In basicstamps@yahoogroups.com, "jelongus" <propellanttech@c...>
wrote:
> Ok guys...I'm working on a project that will interface with a
PCF8583
> RTC wRam. Here is my problem......I have no idea what I'm doing
with
> respect to I2C. I really need someone to break this down to basics
> for me. I'm specifically looking for an alarm from the RCT every
> 1/10th of a second. But Like I said...I don't get the I2C protocol.
>
>
> Any help would be appreciated.
>
>
> James
> Success is 1% inspiration and 99% perspiration. (Thomas Edison)
I have a BS2P40
I'm planning on using the I2C commands. Thanks for the help in
advance.
James
>
> James -
>
> In order to answer your question it would help if we knew what kind
of
> Stamp you're using, or planning to use.
>
> Bruce Bates
>
>
>
>
> >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/
I have read all types of different material from Phillips, as well as
Nuts and Volts, and the Stampworks articles as well.
I just don't seem to get the whole picture about using I2C with the
PCF 8583.
I'm a litle lost about the command structure. I have read so many
things ....now I'm confused. All I want is for the RTC to tell the
Stamp when 1/10th of a second has passed, but every attempt I
make...gives me strange results. I tried to get the RTC to display
(with debug) 100th's of seconds.....but the number is just 000 to
009. It also moves the second digit,but so fast you can hardly notice
it.
That is the reason I came here. You guys probably understand the
communication layout much better than I. I'm really lost when it
comes to I2C. Doesn't make a whole lot of sense.
Thanks,
James
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> Specifications for the I2C protocol are available on the Net from
> Philips. The short story is that it is a synchronous (separate
data and
> clock lines), multi-drop buss. Devices on the buss are addressed by
> type and unit (many I2C devices support more than one of the same
device
> type on the buss).
>
> The BS2p and BS2pe have built-in I2C commands, but you can bit-bang
the
> signaling using SHIFTOUT and SHIFTIN with other BS2 micros. I've
even
> heard that some people have written BS1 code for I2C. Now that I
can
> program my BS1 from Windows (in testing -- you'll get it soon too!)
I
> will give it a try.
>
> Take a look at our Nuts & Volts material -- you'll find Column
#85 "I2C
> Fun for Everyone" useful. You'll find it in the Downloads section
of
> our web site.
>
> If memory serves me, the PCF8583 has a 1 Hz output signal, so for
your
> project you'll need to poll the 1/100th seconds register and work
from
> there.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
you're most of the way there. Keep in mind that the values returned by
the PCF8583 are in BCD, so the value in the high nib of register 0 will
change every 10th of a second. All you have to do is read this register
and look to see if the high nibble changed.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: jelongus [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QqHSI4dIaafIDNxSIfgYTUZfD1rG-bHmR4z_mNTItQq2195KRzcoDOlq1YePSsx-0cGUp-RmTI1T5tGOIIXSZA]propellanttech@c...[/url
Sent: Tuesday, October 07, 2003 12:38 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Sort of a newbie...could use some help!?
Jon,
I have read all types of different material from Phillips, as well as
Nuts and Volts, and the Stampworks articles as well.
I just don't seem to get the whole picture about using I2C with the
PCF 8583.
I'm a litle lost about the command structure. I have read so many
things ....now I'm confused. All I want is for the RTC to tell the
Stamp when 1/10th of a second has passed, but every attempt I
make...gives me strange results. I tried to get the RTC to display
(with debug) 100th's of seconds.....but the number is just 000 to
009. It also moves the second digit,but so fast you can hardly notice
it.
That is the reason I came here. You guys probably understand the
communication layout much better than I. I'm really lost when it
comes to I2C. Doesn't make a whole lot of sense.
Thanks,
James
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> Specifications for the I2C protocol are available on the Net from
> Philips. The short story is that it is a synchronous (separate
data and
> clock lines), multi-drop buss. Devices on the buss are addressed by
> type and unit (many I2C devices support more than one of the same
device
> type on the buss).
>
> The BS2p and BS2pe have built-in I2C commands, but you can bit-bang
the
> signaling using SHIFTOUT and SHIFTIN with other BS2 micros. I've
even
> heard that some people have written BS1 code for I2C. Now that I
can
> program my BS1 from Windows (in testing -- you'll get it soon too!)
I
> will give it a try.
>
> Take a look at our Nuts & Volts material -- you'll find Column
#85 "I2C
> Fun for Everyone" useful. You'll find it in the Downloads section
of
> our web site.
>
> If memory serves me, the PCF8583 has a 1 Hz output signal, so for
your
> project you'll need to poll the 1/100th seconds register and work
from
> there.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
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Could you give me a little snippet of what the command would look
like, to get the High nib of the register. This is the main problem I
think I'm having.
Also....instead of having the stamp watch for the value...is it
possible for the RTC to send an alarm when the register changes. I
know there is an alarm feature....by the Phillips website.
Like I said....I don't really understand all of the I2C protocol.
Jon you are a gret resource to have around.
James
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> If you can read the device (and there is code on our web site) then
> you're most of the way there. Keep in mind that the values
returned by
> the PCF8583 are in BCD, so the value in the high nib of register 0
will
> change every 10th of a second. All you have to do is read this
register
> and look to see if the high nibble changed.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
>
Addr = 0) and when it sees a change in the high nibble of register 1 (I
was mistaken about register 0 earlier) it will print an astersisk on the
debug window. You can change that section to whatever you want
triggered at 10 hertz.
reg1 VAR Byte
old10ths VAR Nib
Setup:
old10ths = $F
Main:
DO
I2CIN 0, $A1, 1, [noparse][[/noparse]reg1]
IF (reg1.HIGHNIB <> old10ths) THEN
DEBUG "*"
old10ths = reg1.HIGHNIB
ENDIF
LOOP
Using the timer alarm output is quite a bit more involved, and requires
another input pin. The PCF8583 specs go into the details.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: jelongus [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=alNF-u1bX8aqymzE8C-TWop6fZrlvPC7gbP5wjQnkigNaIvJ6A-vHNu4ctikCW6dT9NC2vIpw4kzMe8u5ua8RZP-Omx_]propellanttech@c...[/url
Sent: Tuesday, October 07, 2003 2:02 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Sort of a newbie...could use some help!?
Jon,
Could you give me a little snippet of what the command would look
like, to get the High nib of the register. This is the main problem I
think I'm having.
Also....instead of having the stamp watch for the value...is it
possible for the RTC to send an alarm when the register changes. I
know there is an alarm feature....by the Phillips website.
Like I said....I don't really understand all of the I2C protocol.
Jon you are a gret resource to have around.
James
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> If you can read the device (and there is code on our web site) then
> you're most of the way there. Keep in mind that the values
returned by
> the PCF8583 are in BCD, so the value in the high nib of register 0
will
> change every 10th of a second. All you have to do is read this
register
> and look to see if the high nibble changed.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
>
>
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and Body of the message will be ignored.
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This message has been scanned by WebShield. Please report SPAM to
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