Here are the instructions to build a simple temperature logger using a $5.00 I2C temperature sensor. The data is stored to the SD card and can be easily imported into excel. Simply by changing or adding other sensors other types of data can also be collected.
The following components are used for this project:
Raspberry Pi(single board computer)
Temperature Sensor (SF-SEN-11931)
The Zagros Raspberry Pi 2 starter kit also includes everything needed for this project except the temperature sensor!