Lucas have posted useful project in μlabs. Logical analyser is very handy tool when working with digital electronics. Buying one sometimes may be to expensive and not worth an investment. So why not to build one.
Device sends data via USB to PC where it can be viewed and analysed in convenient window. Device uses external RAM which is used as data buffer – this allows to avoid bottel neck of data transmission due to low internal AVR RAM. Project files and necessary software is available for download. Dont be scared description is in German language. So use any translator available on line.