I have been told by my friend who owns an industry to develop for him a logger which he can use to log date and time when there was a power outage in his absence so that his workers don't fake it.

I was thinking of a relay with a 230V coil when there is no supply there will be a switch over off the relay contacts which will result in loging of the data as it is connected to a port pin.

I need to power the system in case of power outage,I was thinking of a capacitor which could power the Uc till the data was logged .

I was thinking of using a 89c51 /52 with 16x2 LCD display

a RTC I am not able make up my mind which to use ds1307 or 1302 which one is simpler to use ?

I looked at data sheet and ds1302 has 26 bytes of nvram and 1307 has 56 bytes which is attractive,but I don't know to program I2C chips,I am still new just a project old...

Please guide me .
Deepak