Easy Data Logger with Virtual USB
“V-USB is a software-only implementation of a low-speed USB device for Atmel’s AVR® microcontrollers, making it possible to build USB hardware with almost any AVR® microcontroller, not requiring any additional chip.”
For further details on V-USB and licensing, visit http://www.obdev.at/products/vusb/index.html
This is a data logger project that reads an analog signal, converts into digital number, and sends it to a host computer using Virtual USB. This is a good example application of V-USB. An 8-pin ATtiny45 microcontroller without an external crystal oscillator is used for this demonstration. The beauty of this project is the ATtiny45 presents itself as a USB keyboard to the host computer, and sends the measurements by itself. All you need to do is to open a text editor on the host computer, and press the Start/Stop button on the data logger. The data will be typed automatically on the editor. The sampling time for data logger is set to 1 sec, and an on-board LED indicates the logger is active.