ds1302 - backup battery
Archiver
Posts: 46,084
I am testing ds1302 RTC using source code from Jeff A MArtin (from
Parallax CD).
But how can I keep the clock ticking while the BS2 is off. I have used
backup battery, but I don't have appropriate source code.
Pls help me.
Parallax CD).
But how can I keep the clock ticking while the BS2 is off. I have used
backup battery, but I don't have appropriate source code.
Pls help me.
Comments
>
Original Message
> From: xiemingsuk [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=2FgAHgiTzCShMIK7yvetJ8zbEc0-Qzb1ojzn9SkvzcfzMod6Kyn2mowC0iPmIcucKqtW-cYy5gPDCw]altraman@d...[/url
> Sent: April 25, 2004 6:08 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] ds1302 - backup battery
>
>
> I am testing ds1302 RTC using source code from Jeff A MArtin (from
> Parallax CD).
>
>
> But how can I keep the clock ticking while the BS2 is off. I have used
> backup battery, but I don't have appropriate source code.
>
>
> Pls help me.
>
>
>
>
>
>
>
> 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.
>
> Yahoo! Groups Links
>
>
>
>
>
>
altraman@d... writes:
> But how can I keep the clock ticking while the BS2 is off. I have used
> backup battery, but I don't have appropriate source code.
>
>
You don't need a code. If you have a backup batt attached to the clock, it
takes over when the regular input voltge falls below the batt voltage.
Sid Weaver
We're always thinking.....
http://www.visualmuses.com/chipcircuit/index.html
[noparse][[/noparse]Non-text portions of this message have been removed]
allan.lane@h... writes:
> However, when your program comes up next time,
> it MUST NOT 'set time' into the 1302, or you'll
> wipe out the time the 1302 has been carefully
> maintaining.
>
I do not think you can reset the 1302 if the battery is connected. I have
found
that to reset the time I have to remove the battery. The data sheet
indicates
that the time can only be set at original startup.
Sid Weaver
We're always thinking.....
http://www.visualmuses.com/chipcircuit/index.html
[noparse][[/noparse]Non-text portions of this message have been removed]
takes over and runs the DS1302 internal clock,
just like your LCD watch.
However, when your program comes up next time,
it MUST NOT 'set time' into the 1302, or you'll
wipe out the time the 1302 has been carefully
maintaining.
--- In basicstamps@yahoogroups.com, Newzed@a... wrote:
> In a message dated 4/25/2004 10:29:25 PM Eastern Daylight Time,
> altraman@d... writes:
>
>
> > But how can I keep the clock ticking while the BS2 is off. I have
used
> > backup battery, but I don't have appropriate source code.
> >
> >
>
> You don't need a code. If you have a backup batt attached to the
clock, it
> takes over when the regular input voltge falls below the batt
voltage.
>
> Sid Weaver
> We're always thinking.....
> http://www.visualmuses.com/chipcircuit/index.html
>
>
>
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
Here is a code that has all of the options listed for battery
backup.
Stephen Swanson
Technical Support Manager
Parallax, Inc.
599 Menlo Drive, #100
Rocklin, CA 95765
Phone (916) 624-8333
E-mail ..... sswanson@p...
Main site...... www.parallax.com
Educational site.... www.parallax.com/sic
Javelin Stamp... www.parallax.com/javelin
Original Message
From: xiemingsuk [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=IyhF0ldXpz_sr8-H788TXtRTEBA600w0IQoC1G5LpbyOFeymTR-v6ZSSiag_Megys76l4Khy8ruvCwx94hXj]altraman@d...[/url
Sent: Sunday, April 25, 2004 6:08 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] ds1302 - backup battery
I am testing ds1302 RTC using source code from Jeff A MArtin (from
Parallax CD).
But how can I keep the clock ticking while the BS2 is off. I have used
backup battery, but I don't have appropriate source code.
Pls help me.
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.
Yahoo! Groups Links
This message has been scanned by WebShield. Please report SPAM to
abuse@p....
[noparse][[/noparse]Non-text portions of this message have been removed]
wrote:
> I am testing ds1302 RTC using source code from Jeff A MArtin (from
> Parallax CD).
>
>
> But how can I keep the clock ticking while the BS2 is off. I have
used
> backup battery, but I don't have appropriate source code.
>
>
> Pls help me.
Hi,
First, check the pin connections. The backup battery is not on the
same pin as the main power.
Second, check the battery power. the chip uses the highest power
input of the two pins, so if your backup is higher than your power
supply you may have to do something to fix that.
On our ChipCircit DS1302 boards, we used a battery holder so we can
replace the battery, but Dallas/Maxim tech support reports that you
can do anything to the clock with the power on all the time. We were
worried about setting the clock and then someone in a different
timezone using it if the battery was soldered on.
But, Vcc2 (pin 1) is the main power and Vcc1 (pin 8) is for the
battery backup. Vcc2 must be 0.02 volts higer than Vcc1.
Also, if you are using a lithum battery, make sure you have the
trickle charger turned OFF. Or, really, make sure you don't turn it
on as it ships OFF by default. A battery will self drain faster than
this chip will drain it. A button will last over 10 years in full
back-up. Also, the button drain will stop when you apply power to
pin1. That means your back-up on a all-the-time powered circuit will
last the life of the battert shelf life. Some papers say 17 years,
others say over 20 for a button. (I'm wondering what a BS will be in
20 years....)
Dave
http://www.visualmuses.com/chipcircuit/index.html