So that others might benefit, I am posting my recent experiences with this breakout board. At first, I thought I had a bad board, but after a day of troubleshooting I found the issue. The symptoms were that the board would accept commands, update the time and provide accurate time readings when 5V were applied to the board, but when the power was removed, all registers would zero out. I tested the battery and it was showing a nominal 3.2V, so looking further, only 20 to 40 mV were seen at pin 3 when the battery was in the holder. Seems as if the battery is shorting itself out on the + solder pads where the battery holder is soldered to the board.

To rectify the problem, I inserted a piece of aluminum foil between the battery and the - battery contact on the board, this lifted the battery enough so that it would clear the + solder pads on the sides and prevent the short from occurring.

I am currently debating on either leaving it as is or returning it for another unit, but since I soldered a header on the board and it is working, I may end up keeping this one.

Sparkfun, why not put the pull-up resistors on the module for us with jumper to disconnect if necessary?

Hi,
I wrote a C# driver targeting the netduino for this clock module. You can find the code and details here:http://fabienroyer.wordpress.com/2011/01/03/keeping-track-of-time-on-a-netduino-using-a-maxim-ds1307-real-time-clock/
Cheers,
-Fabien.

For Arduino Uno users -
I have built on the code John Vaughters included in his tutorial (nice job, btw). Created an RTC library and added the class accessors listed below. Plus, I have a test harness that exercises the library. This is a work in progress (still a little rough, a little light on comments), but if you are just getting started with this nice little 1307 breakout board, perhaps my work might be of some use. Plus, I could use the feedback.
ezcook57@gmail.com
void getTimeDate(struct timeDateContainer* workingPtr);
void printTimeDate(struct timeDateContainer* nowPtr);
void setSeconds(int seconds);
void setMinutes (int minutes);
void setHours (int hours);
void setDayOfWeek (int dayOfWeek);
void setDayOfMonth (int dayOfMonth);
void setMonthOfYear (int monthOfYear);
void setYear (int year);
bool is12HourModeEnabled(void);
byte isItAMorPM (void);
void setAmPm (int amPmDesignator);
void set24HourMode (void);
void set12HourMode (void);
void turn1307On (void); - not yet implemented V 4.0
void turn1307Off (void); - ditto
void readMemoryBlock (byte destinationArray[],
byte numberOfBytes,
byte startingOffset);
void clearMemoryBlock (void);
byte bcdToDec(byte val);
byte decToBcd(byte val);
// should be able to use byte instead of unsigned char?
void I2cWriteUtility (unsigned char newValue,
unsigned char dataOffset,
unsigned char dataMask);
unsigned char I2cReadUtility (unsigned char dataOffset);

Is there any way you could create a module that runs on 3.3V as well?
I found that the DS3231 to be a fantastic replacement. The DS3231 will function with a VCC ranging from 2.3V to 5.5V and has a battery backup. Unlike the DS1307, the DS3231 also has an integrated crystal (so no external crystal required), temperature sensor, 2 programmable time-of-day alarms, a 32.768 kHz output pin, and a reset button debounce circuit. And the DS3231 only costs a dollar more (DS1307 cost is $1.36/1k and the DS3231 is $2.55/1k).

I see that the schematic is for v1.3 and I was wondering if its the same for v1.4? Also, is that a 0 ohm resistor? One last question, what size coin-cell battery holder is that? BOM? Any help would be greatly appreciated!

This module has the following: IC ($1.35), crystal ($0.27), holder ($0.27), 0.56 sq in pcb (~$0.15) capacitor ($0.04), CR1225 (~$0.20) and assembly (~$0.15) for a grand total of $2.43, this even before negotiating with suppliers on volume pricing. Does anyone else think this module is overpriced? For that matter, do all Sparkfun products have such ridiculous margin (approx. 515% margin in this case)? If the answer is yes, I see a real business opportunity here!

How can you use this item with the pcDuino or Raspberry Pi??

.

Yes thanks indeed to John Vaughters. I'd have never got this running on my own. Comments below mentioned pull up resistors. There were none shown on the schematic? So now that I have the clock set, I want to read it as a time stamp for a logger. I'll have to use the libraries and whittle the code for my application. It feels like cheating but I'm still toddling along learning the code and the syntax

Anyone seen a shield for MCP79410 or PCF85063 ? These are quite a bit cheaper than DSxxx clocks. Microchip has AC164140 and NXP has OM11059A,598 SKU for eval, but of course they arent as neat as ones here ..

Just hooked mine up. WOW so easy! I removed the battery to solder it, so the time was 1-1-12 0:0 (or whatever) when I tested it (as I expected). I read through all the comments on here but I liked this guy's example the best. Simple, easy, and got `er done. BTW, that link was http://arduinotronics.blogspot.com/2010/10/ds1307-real-time-clock-working.html

The libraries are nice, but my project has more crap connected to it than anything I've seen anyone else do with an Arduino, so I didn't want yet another include file. The above was nicely KISS.

I wrote a dinky little GUI in java for this device if anyone wants to check it out. Its at my site: http://www.servophilia.com/java.html

does this work at 3.3v?

Is there a serial RTC?

Only up to year 2100? I excpect a new millenium crisis!

Is it possible to get one of these preprogrammed to the time being transmitted from Fort Collins, Colorado By WWVB (and even better delivered before it gains or looses a full second....)?

I like it

Sparkfun, the datasheet is also silent (or at least vague) on the issue of accuracy. Could you please provide a reasonable explanation as to how accurate we can expect this clock to be?

This thing is not very accurate, as others have noted. However, the one I have is very stable. Using this device to produce an accurate time requires a little software to remove the drift. If you do this, it's better to let the clock drift and compute a correction than to occasionally reset the clock. Two of the 56 ram bytes can be used to store a reference time. I have a clock that is working well with this approach.

im having a problem with the module returning for hours minutes and seconds 165:165:85, intermittently... i think it is a power problem, because my arduino mega also freezes.

hii guys..i also got a problem working with ds1307...in my case i got ds1307 working with atmega 8 and i get the correct time display..but when i use atmega 168...it shows 0:0:0...time is not getting display.... my hardware is working perfect.......can anyone help me with this????

The DS1307 is a nice device, but it doesn't keep time very accurately. Its good for a out a minute a week. If you need better timekeeping try the DS3234, its good for about 1 second a week.

While simple, the DS1307 was a bad choice: operating voltage 4.5-5.5V. There are TONS of other great (and cheaper) RTCs which operate as low down as 1V!!!!!

Hi guys, We have just purchased the RTC module from Sparkfun and we thought we could use the "Example 16F88 code" listed above to write it to our PIC16F88, but we have to use the pic basic pro compiler to get it there. We are really new to all of this so we are anxious to learn. Does anyone have code examples that we could use? Thank you for any suggestions.

I followed these directions using analog pins 4 and 5 with my Uno. Ran these 2 sketches:
http://bildr.org/2011/03/ds1307-arduino/
Got
0/0/0 0:0:0
0/0/0 0:0:0
0/0/0 0:0:0
0/0/0 0:0:0
...
Please help!

Can you guys sell the DS1307 alone? I need it for a project and I don't want to solder this board to a PC board...

Wow, be aware, while this is a fine chip for learning purposes (i2C)at stable room temperature it looses about 60 seconds per week.
BTW, this I2C buss chip works fine at 5VDC with the HMC Compass chip on the same I2C buss. I2C pull down resistors either 4.7k or 10K are part of the MHC compass chip.

After modifying some simple code from the Revolution Ed PICAXE forum this little clock operated fine with a 20X2 C.1 firmware. My first I2C experience. Anyway, the draw back is setting the exact time to the second. I guess it would not take too long to write code to read a GPS and synch the time. Another night ...

Yet another library: https://github.com/davidhbrown/RealTimeClockDS1307
Includes example sketch that (via Serial monitor) allows you to set the clock, accurately toggle AM/PM, enable/disable the square wave generator, and read/write memory.
I wanted to use the square wave output to trigger an interrupt and use the battery-backed RAM for a data logger project, so I needed a library that would do a little more than just read the time.

Hello guys,
I wrote a library to make setting and getting date/time from DS1307 easier on Arduino.
The code is available at:
https://github.com/turicas/DS1307/
Please let me know what do you think and, if you want, put a link to this library in the product description.

can some write me some code or show me where to get it to reset the clock to UTC Time

I'd like to use the 1Hz oscillator and the "open drain" SQW pin with an LED and resistor connected in series to the 5V supply.
So far, I'm using a 3K-Ohm resistor to limit the LED to about 1mA (fairly dim). Is this sufficient as a pull-up resistor? A lower value / brighter LED would be nice. A 200-ohm resistor did also work, but I didn't leave it running for a long time. Should I be doing something else, like using SQW to drive my own transistor to switch the LED? Seems redundant, but I'd rather put in an extra part than kill the clock. I can't find anything in the datasheet that refers to allowable current on this pin; presumably it has no problem with the +5V it uses itself.
All the online references to open drains (mostly talking about open collectors actually) I can find seem to be talking about using values up to hundreds of kohm to try to minimize current or dropping back maybe to 4.7kOhm for something like I2C running lots of parallel devices at 400kHz.
The intended application is to help confirm running status of a data logger and so will be blinking away for months on end. I can also leave off the blinky without impairing the essential operation if I'm totally missing the intended use of the pin.

I have the sparkfun DS1307 module hooked to my Arduino Uno on analog pins 4 and 5 that same as this diagram http://bildr.org/2011/03/ds1307-arduino. When I start it up and use the code from the site above to read it reads noon Jan 1 1999. This works fine, however when I try to set the time using the other example sketch provided I get the right time until i close and reopen the serial monitor or turn off everything and turn it back on. If I do either of those things the the time goes back to 1999. Any ideas what could be wrong? Thanks

I want to connect several RTC's at once. Is there a way to change the slave address on a DS1307 and DS3234?

I wasn't paying attention, the battery holder is not a ground. You'll short the battery otherwise and loose time when the device is powered off :)
This device costs more than Adafruit's, but is around a third of the PCB real estate (double sided, SOIC).
John Boxall has some good example code and tutorial as well: http://tronixstuff.wordpress.com/2010/05/20/getting-started-with-arduino-%E2%80%93-chapter-seven/

Is there any possibility to change default (0x68) address on this chip ? I have 4 devices on the I2C bus and they all 0x68.
I am also trying to change the address on the other sensors (K22 Senseair) but without luck so far.
Thank you !

I had troubles getting the example code working with Uno.
I was successful with the RTC library (https://github.com/adafruit/RTClib) connecting SDA - A4, SCL - A5.

My watch uses an mbed as it's brain so if there is some drift in the time I don't much care. Compensation is easy. Especially if I implement wifi. It's conveniently already put together for me :)

One of the mounting holes isn't accessible due to the location of the battery holder.

If anyone had the same problem as me I found the solution, hope it saves you some googling time :) I am also unsure if the problem is connected to the UNO or not which I am using.<br />
<br />
Two issues:<br />
Besides having to switch connectors from RX(0) and TX(1) to using A4 and A5 to get a read, I couldn't set the time with the commands provided, it would just randomly set the time. The TsomeNumbers.. did not work. The problem came with the code supplied in both the wiring example and in the bottom section of the Arduino tutorial.<br />
<br />
I found by using the less(more?) sophisticated code from glacialwanderer.com it works a treat. just remember to comment out the set time line when the time is set :)<br />
<br />
http://www.glacialwanderer.com/hobbyrobotics/?p=12<br />
<br />
Hope this helps!

I got my DS1307 displaying on my LCD module. Posted my code and wiring at http://arduinotronics.blogspot.com/2010/10/ds1307-real-time-clock-working.html
Thank you Sparkfun!

Can't wait! Any ETA? Thanks!

This module is highly useful, especially with Arduino. We have a tutorial about it here: http://bit.ly/amhBeW

Works great, but it was set to a junk time when I got it. It was something like 30:05:00 or something. Had to reset it. Silly Sparkfun :)

I wrote an arduino library to use this. It's available at http://is.gd/880Ju but I don't really have 24 hour time working yet. The archive has a Readme.txt that covers how to use the library including how to wire it to the Arduino.

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

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.

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!

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;(

:) 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/

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? :)

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

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)

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.

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.

Would love to see one of these for a 3.3v part, rather than 5v.