Making your own test equipment can be fun, rewarding and even educational - and one interesting example of doing so has been documented by Joonas Pihlajamaa with his logic analyser based around the Atmel ATtiny2313. The '2313 was chosen as it has eight logic lines on the same port, allowing high-speed detection of logic states with port manipulation. The project can also be adapted to other microcontrollers with the same configuration - such as the ATmega328P. Finally the connection between the analyser circuit and the PC is handled by a simple USB-serial adaptor.
If you're building the analyser or other circuits that need a serial to USB interface, check out our new USBserial module:
It offers much more than the typical FTDI-based adapter. Apart from dual-voltage USB-serial support, it's also a full ATmega16U2 breakout board with all I/O pins arranged for easy access. The board can be flashed easily, and has the pinouts for a USBasp programmer. For more information including our Quickstart guide and of course to order - visit the USB Serial product page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.