Keeping track of date and time

Started by David Sousa Mendes October 6, 2009
Hello fellows
On an old thread, someone suggested the use of DS1302 as an external RTC...
Is there any new/better chip on the market or do you still think this is
the best way to keep track of date and time?

Regards

David M.
David,
I have been using the DS1306 for about 6 years, not sure of the difference from the DS1302 but I can run it on the SPI bus and use a supercap to keep the timer running 2-3 weeks after the power is off. I think it's almost identical code apart from the command to turn on the charger for the supercap.

Ian

--- In b..., David Sousa Mendes wrote:
>
> Hello fellows
> On an old thread, someone suggested the use of DS1302 as an external RTC...
> Is there any new/better chip on the market or do you still think this is
> the best way to keep track of date and time?
>
> Regards
>
> David M.
>

Try PMB-248 GPS from Parallax. It gives you UTC without being in line of
sight with satellites.

http://www.parallax.com/tabid/768/txtSearch/pmb-248/List/0/SortField/4/Defau
lt.aspx

From: b... [mailto:b...] On Behalf Of
David Sousa Mendes
Sent: Tuesday, October 06, 2009 10:10 AM
To: b...
Subject: [BasicX] Keeping track of date and time

Hello fellows
On an old thread, someone suggested the use of DS1302 as an external RTC...
Is there any new/better chip on the market or do you still think this is
the best way to keep track of date and time?

Regards

David M.



Thanks j...@bipsnm.com, but this application will be deployed inside a
cave, so, it will never be in line of sight with satellites... Otherwise
it could be a good option...

Ian, concerning your DS1306:
1 - What is the capacity of your "supercap"?
2 - Do you need an external oscilator, crystal, or whatever? Where can
we buy such a thing?
3 - Do you think you could provide your source code?

Cheers

David

Hello,

I had a quick look of the datasheet of the DS1006 and it does not look very easy to use this IC.

Can you tell me from where you read the data (serial data) , what you have to do to read the data.
It the IC aware of the today date or do we have to dop something to it to write the real date.

What about IC which receive the date from a radio transmiter ?

Thanks and best regards.

Patrick.
--- In b..., David Sousa Mendes wrote:
>
> Thanks john@..., but this application will be deployed inside a
> cave, so, it will never be in line of sight with satellites... Otherwise
> it could be a good option...
>
> Ian, concerning your DS1306:
> 1 - What is the capacity of your "supercap"?
> 2 - Do you need an external oscilator, crystal, or whatever? Where can
> we buy such a thing?
> 3 - Do you think you could provide your source code?
>
> Cheers
>
> David
>

Patrick, my knowledge on the subject is still very scarse...
Regarding radio transmitions, and since I will deploy my system on a
cave, I won't be able to used it neither..
Regards

David M.

David,

> 1 - What is the capacity of your "supercap"?
0.22F part # GC5.5V0.22F

> 2 - Do you need an external oscilator, crystal, or whatever? Where can
> we buy such a thing?
yes I use an external crystal 32.768k with a couple of 18pf caps.
I get all this from Digikey in the US

> 3 - Do you think you could provide your source code?
sure but I will need a couple of days to dig out all the relevant stuff.

Warning: there is something in the SPICmd that sets the pin state opposite from what the CE line of the DS1306 wants. I ended up using a 2N3904 to get the correct input. I did all this 6 years ago, and I don't remember all the reasons, but I have an ugly mod on the back of my board.

Ian

Thanks, Ian
When you have the code, I'll be happy to see it!
Sorry for my bad english, but what do you mean by :
" I have an ugly mod on the back of my board."?

Regards

David M.
David,
mod - hardware modification. Sorry

--- In b..., David Sousa Mendes
wrote:
>
> Thanks, Ian
> When you have the code, I'll be happy to see it!
> Sorry for my bad english, but what do you mean by :
> " I have an ugly mod on the back of my board."?
>
> Regards
>
> David M.
>

Hello fellows
I'm still trying to choose the best MAXIM's RTC for my application...
But in their site:
http://para.maxim-ic.com/en/index.mvp?tree=timers
One can see that they have RTC with several serial protocols: I2C, SPI,
3-Wire, 1-Wire.
I'm a bit lost here...
1 - Which of these protocols can be used with BasicX24?
2 - Can I have 2 SPI chips communicating at the same time with the BasicX24?
3 - Is the 3-Wire protocol the normal serial protocol one uses to
communicate, for instance with a serial LCD?

Cheers

David M.