SparkFun Electronics - Real Time Clock Module

Products

Product Info

Real Time Clock Module

sku: BOB-00099

Description: This a custom designed module for the DS1307 Real Time Clock. The module comes fully assembled and pre-programmed with the current time (ok, so it's our current time - MST). The included Lithium coin cell battery (CR1225 41mAh) will run the module for a minimum of 9 years (17 years typical) without external 5V power. The DS1307 is accessed via the I2C protocol. We've written a test-bed to program the modules. This test-bed code should give you some insight on how to interface the module to any mircocontroller using our example software I2C and BCD routines.

Features:

Two wire I2C interface
Hour : Minutes : Seconds AM/PM
Day Month, Date - Year
Leap year compensation
Accurate calendar up to year 2100
Battery backup included
1Hz output pin
56 Bytes of Non-volatile memory available to user

Dimensions: 0.75x0.75" (20x20mm)

Documents:

Software:

Example 16F88 code
Arduino Tutorial. Thanks John Vaughters!
Arduino Tutorial in Portuguese. Thanks Daniel Gonçalves!

Pricing

	32 in stock backorder allowed

$19.95	price
$17.95	10-99 (10% off)
$15.96	100+ (20% off)

	quantity

click on image to enlarge

Comments

15 comments

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	by codemonkey +1 \| February 12, 2009 at 3:12 PM 0
Would love to see one of these for a 3.3v part, rather than 5v.

	by Colin +2 \| April 16, 2009 at 3:01 PM 0
What's the frequency stability on the crystal? +/-0.5% means that your date/time could be off by almost 2 whole days at the end of a year. 10ppm or less would be nice since that would cut the error to single digit minutes in a year.

	by xyz +1.5 \| April 23, 2009 at 1:11 PM 0
If you want reasonable time keeping I've had much better luck with a DS3231. The only downside is they are about twice the price of a DS1307.

	by chrisspurgeon +3.2 \| June 28, 2009 at 11:46 AM 0
I would love a bit more newbie help with this module. What do "SQW", "SCL", and "SDA" mean? I think I kinda understand how to run the Arduino tutorial, but I'm actually not clear on how to physically wire the thing up.

tzarcone

| July 2, 2009 at 4:51 AM

I found some info on the Arduino Tutorial in Portuguese by Daniel Goncalaves under the "Software" heading.

It shows a photo and diagram and provides some discriptions. I was able to read it in English by entering the URL into Google search and then use [translating this page] feature.

I haven't connected my clock yet, so I don't know how accurate the info is.

http://lusorobotica.com/index.php/topic,681.0.html

Cheers,
Troy

	by tzarcone +1 \| July 2, 2009 at 3:37 PM 0
Since my last replay, I attached the bob 00099 to my arduino duemilanove 328. bob to Arduino --------------- SDA to Analog Pin 4 SCL to Analog Pin 5 5v to 5v Gnd to Gnd I'm able to program and read from it using RTC Control v.01 by <http://www.combustory.com> John Vaughters Cheers, Troy

	by Japalan +2.1 \| July 13, 2009 at 6:39 AM 0
Doc + schema + code in one page. Get it running in just the time of soldering the wires. One big difference with tzarcone, I must not plug the ground wire, otherwise reading is always the same. Hope this helps. http://kalshagar.wikispaces.com/Arduino+and+a+Real+Time+Clock+(RTC)

Kshatrya

+1.6

| August 30, 2009 at 4:31 PM

Nothing's incrementing.

I can read from, and write to the RTC, but the time isn't incrementing. I've tried setting/clearing bit 7 of 0x00, running with/without ground and with/without 1K pull-up resisters. Still no action.

I've tried the code from Combustory, as well as my own more abbreviated code.

Heck! I even tried removing the B/U battery to reset everything to zero!

Can anyone suggest something new to try?

Jim
Victoria, BC

	by Kshatrya +1.6 \| September 6, 2009 at 5:01 PM 0
OK, it's working now. The module I received had a faulty crystal. No clock, no increment. Who'd have thought? -G-

	by Attie +5 \| September 27, 2009 at 6:16 AM 0
Im thinking not... but just incase: Is this compatiable with a 3.3v arduino and other 3.3v I2C components? If not are there any plans for a 3.3v part? :)

	by eXtreme +1 \| October 26, 2009 at 8:40 PM 0
:) Hello, I have written a tutorial to interface DS1307 Chip with AVR MCUs. You can have a look at it here http://extremeelectronics.co.in/avr-tutorials/interfacing-ds1307-rtc-chip-with-avr-microcontroller/

	by kewakl +2.9 \| November 22, 2009 at 4:12 PM 0
Kshatrya: OK, it's working now. The module I received had a faulty crystal. No clock, no increment. Who'd have thought? -G- Mine arrived with Register-0 Bit-7 SET! No Clocking. Hmmmmm. I guess that the date/time is wrong.... Thanks for setting it at SparkFun;(

	by GB +2.5 \| January 18, 2010 at 10:35 AM 0
codemonkey: Would love to see one of these for a 3.3v part, rather than 5v. What this guy said. 3.3v version please. Have a look at the DS1338 or DS1388. I don't think you even need to change the PCB!

	by Ifor +2 \| January 22, 2010 at 11:48 AM 0
Like the guy said 3.3V needed did not realise it was 5V only. Just ordered myself the 1338 hope my soldering ip up to it.

	by SlyVixsky –6.3 \| February 4, 2010 at 5:27 AM 0
personally, i prefer the 24 hour version, so though it goes against sparkfun, http://www.newark.com/maxim-integrated-products/ds1307z/real-time-clock-ic/dp/08J6234