One of the great things you can do with an Arduino and very little effort is logging data - and most methods generally write data to a microSD card for later analysis by a PC. However we'd like to illustrate another method by Ray Burne - which uses a microcontroller with the Arduino bootloader and external circuitry directly connected to a PC's USB port. The device then reads the status of 14 I/O pins and sends it back to the PC as text - which is made possible by the device acting as a USB keyboard. This opens up more interesting possibilities such as having the data "typed" straight into a spreadsheet or other software.
If you're wanting to reproduce the project above - we've got you covered with our new ATmega328P MCUs with Arduino Uno bootloader:
This is the same Atmel AVR ATmega328P microcontroller used in the official Arduino Uno, as well as our Eleven, EtherTen, USBDroid, and other boards. Perfect for building your own Arduino-compatible project directly on a breadboard or on a custom PCB, or for replacing the MCU in an existing board. Comes with the Arduino Uno bootloader pre-installed. Better still, it even has a special label stuck on top with details of the pinout, so you don't even need to look up the datasheet when connecting it up in your project! For more information and to order, click here!