Access I2C Bus Internally and Externally on DE0-Nano

That would definitely work, it just seems like a little bit of a waste to add in another core though.

I also looked into the ADC on the board yesterday and realized it runs off SPI, which means I need a SPI module anyway. Since I already need the module I might as well connect it up to accelerometer too. However I have already run into a problem here as well. It appears that the accelerometer was only connected in 3-Wire SPI mode. The SPI core I plan on using doesn't support 3-Wire SPI and I can't modify the circuit to bridge the connections with a resistor, so it looks like SPI might be out of the question too.

Any other suggestions? A second I2C core would work, but I'm mostly interested in if it's possible to connect two busses in general, either through HDL or through connecting pins using the pin planner.

Thank you for your help,

Chris