Bonus Lesson -- Data Logger

With the additional purchase of a micro SD card reader, you can add file storage to your Uno. This project creates a data logger which you can use to store readings from a sensor of your choice. What is a data logger? This gizmo allows you to save sensor data to a SD card using your Uno, and then later use a laptop or other computer to read and analyze the data, make plots and so forth. Data is saved as floating point values, one per line, perfect for reading into Excel and other data analysis programs.