change I2C address on RTC breakout board ?

Adafruit Ethernet, Motor, Proto, Wave, Datalogger, GPS Shields - etc!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
ahdavidson
 
Posts: 131
Joined: Wed Jun 03, 2009 9:59 am

change I2C address on RTC breakout board ?

Post by ahdavidson »

Is it possible to set the I2C address on the RTC breakout board ?

On the LCD backpack, you can solder jumpers to change the address, which is handy. I was just wondering if you could do something similar on the RTC breakout board.

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: change I2C address on RTC breakout board ?

Post by adafruit_support_bill »

No. The DS1307 address not configurable: http://datasheets.maxim-ic.com/en/ds/DS1307.pdf.

User avatar
ahdavidson
 
Posts: 131
Joined: Wed Jun 03, 2009 9:59 am

Re: change I2C address on RTC breakout board ?

Post by ahdavidson »

So to confirm, then...

To use this with another I2C device that has the same default address, you must change the address of the other device on the bus?

This came up because I want to use your LCD backpack with the RTC and had to change the LCD address to something other than zero, by soldering the jumper and changing the LCD init code.

This worked, I'm just repeating it here for future forum searches.

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: change I2C address on RTC breakout board ?

Post by adafruit_support_bill »

That is correct. The 7-bit DS1307 address is 1101000

stephanie
 
Posts: 295
Joined: Sat Dec 11, 2010 1:17 am

Re: change I2C address on RTC breakout board ?

Post by stephanie »

I'm surprised that you ran into a conflict between the LCD backpack and the RTC breakout board. The DS1307's address is 0x68 and the LCD backpack's default address is 0x20.

I've got a chronodot (uses the same address as the DS1307 & can use the same RTC library too) and an LCD backpack (on the default address) running together without any trouble.

User avatar
ahdavidson
 
Posts: 131
Joined: Wed Jun 03, 2009 9:59 am

Re: change I2C address on RTC breakout board ?

Post by ahdavidson »

Hmm, I'll go back and double check. Thanks for the info.

Locked
Please be positive and constructive with your questions and comments.

Return to “Arduino Shields from Adafruit”