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[General] TWO RTC- DS1307 Interfacing with any microcontroller Using I2c

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Aug 28, 2015
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1.How to interface 2 RTC DS1307 with any microcontroller ??
2. wheather address for 2 devices will be same address or different address (NOTE:Both connected in same bus) and why explain it please

They will not work on same bus without multiplexing. Use two buses will be easier I assume.

Hi cnandha19,

The address of slave depends on address lines(hardware), go through DS1307 datasheet. Observe the pinning diagram then you come to know about it.

In software also can configure different address for different slaves on the same bus.

Let me know if you need more information..
Connecting dual DS1307 on the same line will not be possible due to the address of the device which is 1101000 for all the DS1307. So it is not possible to change the address of the part. If you want to use same line for connecting dual RTC's then another type of RTC which works on I2C whose device address will be different. So that you can able to connect on the same line or else use same DS1307 but with different lines for two devices.

Even in Maxim Integarted website they were not shown any glimpses of connecting dual DS1307 on the same bus. Attaching the snapshot found on the website which could be useful if you are willing to use different RTC.


For DS1307 as a slave device has a fixed address. However, why did you need two of the rtc? One can solve multi time application. Meanwhile, you can use a bilateral switch to select the SCL and SDA terminal of any one of the device. Also logic base mosfet can also be use.
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