For SPI debugging the OP may be better off with a scope with the ability to decode SPI and other serial formats. The reason being that bugs with SPI, I2C, RS232 etc are often to do with bad signals which a logic analyser will not show. The Picoscope range includes multi channel scopes, some with built in logic analysers and some with very large sample buffers at prices from about £150 to £10k. I have a range of scopes available but the Pico is my first choice device for this sort of work. www.picotech.com MK