I2C Multiple Pullup Resistors

Hi all,

What are the effects of having multiple different pullup resistors and level shifters on one I2C bus? For example, I have a DS1307 real time clock at 5V with pullups, a BMP085 pressure sensor breakout board with it's own pullups and level shifting, and a LSM303 digital compass breakout board with its own pullups and level shifters. Using all three of them at the same time works just fine, but I am wondering what the side effects of having so many levels and different pullups are on the I2C bus.

Thanks in advance!

The side effects are that you are asking the driving device to sink more current. The arduino is capable of doing this. Check the data sheets for the other devices.

Hi Grumpy_Mike,

Thank you very much for your quick reply, that answers my question perfectly!