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Article #2116Re: Help: 8-Bit O/P from Real-Time Clock Chip
From: John Fields
Date: Sat, 08 May 2004 00:00
Date: Sat, 08 May 2004 00:00
28 lines
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2677 bytes
On Fri, 7 May 2004 19:22:25 +1000, "Darrin" <darrin_2000au@yahoo.com>
wrote:
>To those in the know:
>I am after designing a Real-Time Clock circuit with 8 Data output lines,
>such that at a specific time of the day it should output a set pattern of
>data on its output, hold this data at the outputs for exactly 3 hours, then
>revert to default (defined) for the rest of the day. Further, this change
>should only happen during weekdays and not weekends or public holidays. I am
>hoping to achieve this by using a RTC chip. I am presently looking at a
>chip which I believe may be able to do this (RTC-62421). Has anyone used
>this chip before or have any information like datasheet, specs etc...? Any
>ideas or suggestions appreciated.
---
I've used a Dallas/Maxim DS1307
http://pdfserv.maxim-ic.com/en/ds/DS1307.pdf
for a similar application, and used its internal 56 X 8 non-volatile
(battery backed-up) memory to hold the data. It communicates over a
two-wire bidirectional bus, so you'll need a �C of some flavor to talk
to it. One nice thing about it, IIRC, is that with a 7.5mAH lithium
battery for backup it'll keep time _and_ retain the data written into
its RAM for over 10 years.
--
John Fields
Technical Details
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