Data Acquisition and Analysis for Children
The Measure activity on the XO accepts electrical signals through the sound port, and displays them on the screen. This makes the XO into a digital oscilloscope. The signal can be displayed in time domain, graphing signal strength against time, or in frequency domain, with a sequence of signals subjected to the Discrete Fourier Transform to break it into different frequency components. By applying signal processing, analysis and statistical algorithms to signals in either domain we get a powerful tool for scientific or engineering inquiry.
Any available physical effect can be used to generate a controlled electrical voltage, allowing it to be measured through the sound port. There are also numerous measuring devices with USB interfaces. We can analyze data from them in the same way.
We can also put control signals out based on measurements made. With these signals we can control experiments, or create systems to control devices of many kinds: for example heating, cooling, lighting, irrigation, patient care...
The camera in the XO can capture digital images and videos, including time-lapse video. Two-dimensional image processing and analysis and three dimensional video analysis are also powerful tools.
What, then, should children inquire into? Why, everything within reach, of course. They should be the William Gilberts, Luigi Galvanis, Alessandro Voltas, Ben Franklins, Count Rumfords, Humphrey Davies, Christian Ørsteds, Wilhelm Röntgens, Anders Jonas Ångströms, Thomas Edisons, Nikola Teslas, Marie Curies, George Washington Carvers, Buckminster Fullers, Francis Cricks, and James Watsons of their nations and peoples.
