Raspberry pi i2c digital temperature sensor mcp9808
This I2C digital temperature sensor is one of the more accurate/precise we've ever seen,
With a typical accuracy of ±0.25°C over the sensor's -40°C to +125°C range and precision of +0.0625°C.
They work great with any microcontroller using standard i2c.
There are 3 address pins so you can connect up to 8 to a single I2C bus without address collisions.
Best of all, a wide voltage range makes is usable with 2.7V to 5.5V logic!