Sorry mattallen37, I totally missed that you had a Mega - I was also unaware of the 10K resistors there.
Looks like they are part of a very little 8-pin package as well, so not removable.
On page 3, which signals are being used for I2C? The DIGIAI0 and DIGIAI1 type signals?
Okay, looks like TWCK & TWD pins.
I can't even tell going from the data sheet which pins are actually used for I2C.
However, that series 4.7K resistor is a killer.
This doc desribes the I2C pins:
LEGO MINDSTORMS NXT Hardware Developer Kit.pdf
Not real I2C tho. No open drain pins, the NXT must be master, you have to control the direction of the lines in software.
I was thinking a buffer chip like this one:
"The TXS0102 can be used to bridge the digital-switching compatibility gap between two voltage nodes to
successfully interface logic threshold levels found in electronic systems. It should be used in a point-to-point
topology for interfacing devices or systems operating at different interface voltages with one another. Its primary
target application use is for interfacing with open-drain drivers on the data I/Os such as I2C or 1-wire, where the
data is bidirectional and no control signal is available. The TXS0102 can also be used in applications where a
push-pull driver is connected to the data I/Os, but the TXB0102 might be a better option for such push-pull
applications."
Not sure if the 3V source driving thru a 4.7K will be enough still.