[SOLVED] PIC16F877 RTC using TMR0 or DS1307. Advantage vs Disadvantage

Hi Guys

I am trying to figure out which is best way to approach this. What are the dis-advantages and advantages of either options?

Option 1: 877 using tmr0 to create RTC

Option 2 877 using DS1307 RTC.

I would like to see what everybody's opinion is.

Hi WStevens_sa,

Both are equal in accuracy (assume high quality+accuracy crystal is used for PIC);
If power consumption, no hassle on coding and circuitry is considered DS1307 RTC is good,

Thank you,

Hi,
What DineshSL forgot to mention (but he probably meant it with "no hassle on coding") is that DS1307 is a real watch/calendar and you don’t have to move a single coding finger to have the time and date in a displayable format (BCD), while with the PIC you mentioned you have to do all the work yourself (like we’ve seen in a previous post).

If your crystal is accurate and you add a battery to your DS1307 design, you can have a running watch/calendar for years to come, even with the PIC powered down. In these conditions, keeping a running watch is way more power efficient that having the PIC do it in software.

The only drawback, if any (besides the added BOM cost to the design), is the added complexity of the I2C interface that this circuit has. But this shouldn’t be an issue since the PIC you mentioned also has the I2C capability in the hardware.

Arthur

Hi,

Don't forget the third way - a 32k crystal RTC on Timer 1 - is one of the functions Microchip built in.
You might find other better uses for Timer 0..

Wow thanks guy's for all the replies. Everybody gave helpful information.