DS1307 don't automatically update of day of week?

[codewiz]

Hi.
I am new to using DS1307, though i have been able to make it work. But I thought after setting the date and time that the day of the week will automatically be set. it only changes at 12 midnight.
I want it to set the DOW anytime I do a new setting of date. Must i always set the day of the week?
Please, what do i do? help.

 

[keith1200rs]

I haven't used it but I would assume you would have to set the day of week as well as date and time. RTC chips are simply counters so I wouldn't expect them to automatically calculate the day of week from a given date. If they did that then they wouldn't give you the option of setting the day of week as well.

Keith

 

[Rohi231]

Which processor you are using?

 

[keith1200rs]

Which processor you are using?

I cannot see that is relevant.

Having looked at the datasheet now it is clear that the DS1307 does not and cannot calculate the day of the week given the date because the day is simply a number and how you interpret that number is up to you. You could choose the number 1 to mean Monday or Saturday, whatever you like. The DS1307 simply increments it at midnight without ever knowing what meaning you attribute to it.

Keith.

 

[codewiz]

Thank you Keith.

I have to make do with that.
if i may ask, is there any RTC that could do the automatic day of the week calculation?