DS1302 Seconds Register Tech Support helped me with this Thank YOU ( reslo

sam_sam_sam

What Do I need to just read the Seconds Register··as far as· VAR··· and··· CON··· ·?

·I do not want to read it in the BURST MODE

I just want to use the Second Only

Is there a way to do this and how would I do this is there· a DEMO CODE out there on the Forum that·I could·use

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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 6/5/2009 12:22:57 AM GMT

InSilico

The datasheet says that you can initiate single-byte reads or multi-byte reads (the so-called "burst" mode). The seconds register is only a single byte, so you can read that one register only.

Simply send the hex command value $81 and the chip will read the seconds register and you can clock it into your microcontroller.

Page 9 tells you the addresses of all the time registers and their contents:·http://www.maxim-ic.com.cn/pdfserv/en/ds/DS1302.pdf


Post Edited (InSilico) : 5/31/2009 10:34:36 PM GMT

sam_sam_sam

InSilico

Thank You for your Reply

I try ed this but this only works if you have cap on the DS1302 Chip

When I do this with NO·Cap I only get (80) ·for out put

This is why I ask What VAR and CON

What else·is need to make this work



HIGH CS_1302

SHIFTIN Dio,Clk,LSBPRE,[noparse][[/noparse]secs]

LOW CS_1302

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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 6/2/2009 12:23:00 AM GMT

Timmoore

The second register reading 80 hex (I assume) means hte clock isn't running.If you dont have any battery backup on the clock it will stop when you remove power. You need to write the time to the clock and then set the most significant bit of the seconds register to 0 to start the clock

sam_sam_sam

Here is the routine in case some one else dose not understand how to read only·the second register· you can also do the hours and minutes and so on

Set_Secs:······················································ ·' DS1302 Write Seconds
· HIGH CS1302················································ ·' Select DS1302
· SHIFTOUT DataIO, Clock, LSBFIRST, [noparse][[/noparse]WrSecs]
· SHIFTOUT DataIO, Clock, LSBFIRST, [noparse][[/noparse]secs]
· LOW CS1302················································ ·' Deselect DS1302
· RETURN

Get_secs:······················································ ·' DS1302 Read Seconds
· HIGH CS1302················································ ·' Select DS1302
· SHIFTOUT DataIO, Clock, LSBFIRST, [noparse][[/noparse]RdSecs]
· SHIFTIN DataIO, Clock, LSBPRE, [noparse][[/noparse]secs]
· LOW CS1302················································· ·' Deselect DS1302
· RETURN



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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 6/5/2009 1:13:45 AM GMT

sam_sam_sam

UpDate




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··Thanks for any··that you may have and all of your time finding them

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Sam

Post Edited (sam_sam_sam) : 6/5/2009 1:19:25 AM GMT