i2c pin confusion on the Uno

I am looking at tutorials for how to connect the SRF08 ultrasonic rangefinder to the Uno. I do not have one yet but was thinking of picking one or two up. This is an i2c device, and every tutorial says to connect the SDL and SDA lines to A4 and A5.

However, the Uno has unlabeled SDL and SDA connecters near the AREF and GND connectors near the ICSP connector. This brings up a few questions.

  1. Are the unlabeled connectors near AREF and GND connected to A4 and A5? In other words, if I am using those connectors can I not use A4 and A5?

  2. Do the unlabeled connectors have pullup resistors already or do I need to provide those? I believe the Arduino Mega has built in pullups on the SDL and SCA but I'm not sure about the Uno.

Thank you for the help!

(1) Both sets of pins go to the same pins in the microprocessor so you cannot use A4 and A5 for something else while you are using the pins near AREF for I2C.

(2) I can't find any pull-ups on the diagram that is called a 'schematic' (but is not) and it is not likely that the designer of a general purpose microprocessor board would include those resistors.

Edit: I did find them on the 'schematic' for the mega, not a good design choice in my opinion.

Don