I2C Multiple Pullup Resistors

Using Arduino Networking, Protocols, and Devices
#1

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!

#2

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.

#3

Hi Grumpy_Mike,

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

#4