Controlling PCF8583 clock chip with a PIC

From: John Gruenenfelder (
Date: 12/03/04

Date: Fri, 03 Dec 2004 14:25:57 -0700

I have a board set up with a PIC16F877 microcontroller and on the I2C bus
I have a Phillips PCF8583 clock/alarm chip.

I am attempting to use the alarm function of this chip and thus far am
having almost no luck getting it to work. I know the I2C bus is good
because I have several other devices on it plus the clock function of this
chip is working fine.

Specifically, no matter what type of alarm I instruct the chip to enable
(i.e. daily, weekly, etc.) none of them seem to function. I can test this
by checking the interrupt output pin of the chip with a scope. The
interrupt generation is enabled, but nothing shows on the pin.

I realize this is rather general. My hope is that somebody else has used
this chip and may be able to help me with my problem. If, by any remote
chance, you have, please contact me or post a followup.

--John Gruenenfelder    Research Assistant, Steward Observatory, U of Arizona
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