Re: I2C LED matrix on the Raspberry Pi
Actually, I2C support is compiled into the Wheezy kernel, but is blacklisted in the boot, as it isn't needed by the normal user. Removing that blacklist entry, and adding a modprobe for i2c-dev will create the /dev/i2c-0 device. Installing i2c-tools provides a high-level view of the I2C interface.
The command sudo i2cdetect 0 will show the 8x8 matrix attached to the system as device x'70'. I just have no idea how to use /dev/i2c-0 from that point to use the display. Actual documentation for the I2C Backpack and its supported command structure would go a long way to making the device usable on the Raspberry Pi. At this point it is not an electronic problem, just one of documentation.