PCF8583 problem plz help!

[X4ce]

hey!

Im interfacing 16F877A with PCF8583 to display time on 7Seg.

I've used Nigel Tutorial #6 (I2C Board) but i didnt find any 32KHz but 32.768KHz with 20pf capacitor.

But my clock is running really fast, its counts 1min in just 25sec.

Do i need to use 32KHz? But i didnt find it anywhere in local market.

Then i used capacitor trimmer and tunned it but time elapsed at the same rate or not at all.

Please help i need to submit this project in 3 days.

thanks in advance

X4ce

 

[eblc1388]

Rest assure that by 32KHz crystal, it always refer to a crystal operating at 32.768KHz, the frequency which is also 2 raised to the fifteen power.

When divided by 2^15, this give one pulse per second.

You will be searching for days if not weeks for an exactly 32KHz crystal.

But my clock is running really fast, its counts 1min in just 25sec.

Most probably programming error and nothing to do with the crystal.

 

[X4ce]

my i2c baud rate is 100kbps and my bus pullups are 12Kohm, is dat the probelm?

 

[X4ce]

i got it working, crystal was bad i replaced it by a 32768 crystal which i got from mouse