The BS1USB module is a BASIC Stamp® 1 microcontroller with an on-board USB interface and USB-A connector. Headers provide easy access to all eight BASIC Stamp I/O pins; Vdd (+5 V) and Vss (ground); the USB port supplies 5 V to the module. This handy little device is perfect for adding a user-definable function to your PC. For example, with a few lines of code and a little hardware, you can create a project timer/data logger to keep track of how much time you spend on a particular project that uploads the tallied information to your PC. Downloads: BS1USB Documentation v1.1 (.pdf)