This is an I2C/1-Wire breakout board for the Raspberry Pi. I'm intending to use it in combination with one of Adafruit's 16x2 LCD panels as part of a temperature controller for a fermenter. It includes level converters for the I2C and 1-Wire buses, a real-time clock with battery backup, a switchable output for a solid-state relay, and a barrel connector to power the whole stack with a 5V wall wart. Power and the I2C and 1-Wire buses are brought out to an RJ45 connector for easy connection with Cat5 UTP or similar cable (pairs 3/6 & 4/5 carry power and 1-Wire, so modular phone cord may be sufficient for applications where you don't need I2C).