DS1302 Question

Archiver

I am working with a DS1302 timekeeping chip and would like to setup the
backup power for this using a diode and capacitor.

The documents leave the choice of a diode and capacitor up to the user.
I have no idea what to use.

Could someone recommend, including part numbers if possible, a suitable
diode and capacitor combination?

I am interested in it holding power for at least a couple of days.

Thanks in advance.

Archiver

I know this is basic, but, I feel like a monkey doing a math problem...

I'm trying to display the current time, using a DS1302, in hh:mm format to a
serial LCD. The display seems to work, but, I'm screwing up the math
somewhere on converting the time from the DS1302 raw time format to the
format I need. Below is the formula I'm using, basically, it's not
converting over 60 minutes (ie current time on the clock is 12:88, it's been
runnig for several hours.) What am I missing?

SEROUT LCD_SER, N9600, [noparse][[/noparse]DEC2 12 - (24 - (hrs10 * 10 + hrs01) // 12), ":",
DEC2 mins]

Thanks for the help,
Matt

Archiver

CHECK THE DATA SHEET. Time output is in BCD.

Matt Georgy wrote:

>I know this is basic, but, I feel like a monkey doing a math problem...
>
>I'm trying to display the current time, using a DS1302, in hh:mm format to a
>serial LCD. The display seems to work, but, I'm screwing up the math
>somewhere on converting the time from the DS1302 raw time format to the
>format I need. Below is the formula I'm using, basically, it's not
>converting over 60 minutes (ie current time on the clock is 12:88, it's been
>runnig for several hours.) What am I missing?
>
>SEROUT LCD_SER, N9600, [noparse][[/noparse]DEC2 12 - (24 - (hrs10 * 10 + hrs01) // 12), ":",
>DEC2 mins]
>
>Thanks for the help,
>Matt
>
>
>
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Archiver

When working with the 1302 just use hex modifier dec2 hex hours
and it comes out correctly it is a form of BCD without the
letters

---

Original Message

---

From: "Matt Georgy" <mgeorgy@d...>
To: <basicstamps@yahoogroups.com>
Sent: August 08, 2002 10:29 AM
Subject: [noparse][[/noparse]basicstamps] DS1302 Question


I know this is basic, but, I feel like a monkey doing a math
problem...

I'm trying to display the current time, using a DS1302, in hh:mm
format to a
serial LCD. The display seems to work, but, I'm screwing up the
math
somewhere on converting the time from the DS1302 raw time format
to the
format I need. Below is the formula I'm using, basically, it's
not
converting over 60 minutes (ie current time on the clock is
12:88, it's been
runnig for several hours.) What am I missing?

SEROUT LCD_SER, N9600, [noparse][[/noparse]DEC2 12 - (24 - (hrs10 * 10 + hrs01) //
12), ":",
DEC2 mins]

Thanks for the help,
Matt



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/

Archiver

Hi Matt,

use 'HEX2 mins' instead of DEC.

88 is HEX 58 which is what you want.

Cheers
Col

--- In basicstamps@y..., "Matt Georgy" <mgeorgy@d...> wrote:
> I know this is basic, but, I feel like a monkey doing a math
problem...
>
> I'm trying to display the current time, using a DS1302, in hh:mm
format to a
> serial LCD. The display seems to work, but, I'm screwing up the
math
> somewhere on converting the time from the DS1302 raw time format to
the
> format I need. Below is the formula I'm using, basically, it's not
> converting over 60 minutes (ie current time on the clock is 12:88,
it's been
> runnig for several hours.) What am I missing?
>
> SEROUT LCD_SER, N9600, [noparse][[/noparse]DEC2 12 - (24 - (hrs10 * 10 + hrs01) //
12), ":",
> DEC2 mins]
>
> Thanks for the help,
> Matt