# Is there a way to use the i2c interfaces on a standard PC mainboard to control a device?

I have attached a few sensors and an LCD display, all of them having an I2C interface, to my raspberry pi, and written a software on the pi to read/write them. Right now, I have a network daemon running on the pi to retrieve data to my PC, and control the display from the PC. I would like to, if possible, omit the pi, and control the devices from the PC directly.

The PC has several /dev/i2c* devices, and I can use i2cdetect to list them:

root:~# i2cdetect  -l
i2c-3   smbus       SMBus PIIX4 adapter port 4 at 0b00  SMBus adapter
i2c-1   smbus       SMBus PIIX4 adapter port 2 at 0b00  SMBus adapter
i2c-6   i2c         NVIDIA i2c adapter 5 at 8:00.0      I2C adapter
i2c-4   i2c         NVIDIA i2c adapter 1 at 8:00.0      I2C adapter
i2c-2   smbus       SMBus PIIX4 adapter port 3 at 0b00  SMBus adapter
i2c-0   smbus       SMBus PIIX4 adapter port 0 at 0b00  SMBus adapter
i2c-7   i2c         NVIDIA i2c adapter 6 at 8:00.0      I2C adapter
i2c-5   i2c         NVIDIA i2c adapter 3 at 8:00.0      I2C adapter


So, there are some I2C adapters on the Southbridge, and some more on the video card.

Are any of those likely to be "visible" somewhere I can get to them without having to solder my mainboard? If so, where would I have to look? i2cdetect -y finds several devices attached to i2c-0, but none to i2c-1, i2c-2 and i2c-3, so I guess using one of the latter should be safe to use as long as I'm not adding any other peripherals which might use them.