A basement full of old books but no way to monitor humidity and temperature. Enter a Raspberry Pi. This hacker has put together a DHT22 sensor and an LCD screen with the Pi in order to monitor environmental conditions in his basement. The collected data is then output to a .csv file so that he can see the results over time. He’s written the whole thing up as a walk-through tutorial. Read it here. It’s a great introduction to environmental sensors. A possible extension to this is to publish the results online with a stats service so that he can monitor trends in real time as the results are sent to the service.