Description: This is the SparkFun Real Time Clock (RTC) Module, this little breakout that uses the DS1307 to keep track of the current year, month, day as well as the current time. The module comes fully assembled and includes a small CR1225 Lithium coin cell battery that will run the RTC for a minimum of 9 years (17 years typical) without an external 5V power supply.
The DS1307 RTC is accessed via the I2C protocol. We’ve written a test-bed to program the modules, this code should give you some insight on how to interface the module to any microcontroller using our example software I2C and BCD routines.
This rev of the Real Time Clock module finally adds I2C resistors and a larger battery pad to fix the problems with the battery shorting to the board.
Dimensions: 0.75x0.75" (20x20mm)
Based on 5 ratings:
2 of 2 found this helpful:
NOBODY told me you had to SET THE CLOCK !!!! There was a lot about it was set at the factory and would go for 17 years, but nothing about that I had to set the clock. I found it in an obscure tutorial on the use of PICAXE and the I2C serial communication protocol. Please note on your SPARKFUN data spec that the breakout board has to have the data SET with a HI2COUT instruction !
1 of 1 found this helpful:
Easy to use, I needed to set the clock too but it is easily accomplished with one line from RTClib (google it)!
Almost the smallest I’ve found. However, I’m designing a board that could use any available RTC. Adafruit, Ebay finds, etc. They mostly have similar pin configurations, except for this one. I’ll have to include two header options, because the small size outweighs the inconvenience.
Preferred this over the “Dead On RTC”, as the I2C is easier to connect than the SPI on the ICSP for the boards i use. The product worked as intended out of the box. The clock may have been programmed, but i didn’t check. Piece of cake!
Being a thickheaded lout, the (typically awesome) SparkFun hookup guide would have been helpful to me. Still, i muddled through. I did use the AdaFruit branch of the JeeLabs library. (So i owe those folks.)
Worked right out of the box! All I had to do is solder on a header and unsolder the solder jumpers that pulled up the SDA and SCL to +5V since the Raspberry Pi I was connecting to already has pullups to +3.3V on-board. A bit of code, 4 wires to connect, and I could read and write the time registers to set and read the time.