finst

my application is switch on the lights after half hour in sequence.
i want to use real time clock.any real clock chips are available or not. if it is then can u send me details of it .

and i want to interface clock into microcontroller,tell me is it possible.

Nigel Goodwin

There are various real time clock chips available, have a look at my PIC tutorials at http://www.winpicprog.co.uk which have a tutorial using a Philips PCF8583 I2C clock chip. Dallas are another manufacturer of popular clock chips.

udi_hakim

You should get the DS1643 or the DS12c887 , i just did a project with the 12887 and its working grate.
it will be cheaper to pull it out from an old motherboards then buy it ...

jem

Seems to me that you need a timer instead of an RTC. However, if you need an RTC (and are in NA) try digikey for NJU6355. It is the cheapest RTC around. It does not have an alarm function, and requires four wires to interface. However, the timing can all be generated with SW delays. HW is minimal too: just the chip and a 32.768 XTAL (plus some additional circuitry if you need to keep the clock running on batteries when the rest of the HW is powered down (battery back-up).

kentken

I have had good luck using the DS1307, It uses a standard I2C interface, and sends data in BCD format. Depending on your overhead, setting up a timme 1 with a 32.768kHz Xtal. I have used both types, and had good luck. Feal free to ask more.


Kent