Recently, a need arose to take humidity readings of a crawlspace, over an extended period of time. An Arduino clone called the Bare Bones Board (BBB) is used in this project, mainly for its ability to be mounted to a breadboard.
Using a commercial-off-the-shelf sensor and microSD card, the logger takes temperature and humidity readings at a predefined time interval and writes the readings to a text file on the card. An Octave/MATLAB script is shown that plots the results.
All source code can be found on GitHub.