[milesvp]

Low end analyzers are good for slow signals. 24Mhz is a common sampling rate for less than $30. Just remember that your bus needs to be less than half that speed, and even then the analyzer may lie to you if your bus speed is anywhere near half your sample rate. Also the timings in your bus can greatly effect what the logic analyzer will show vs what the cpu sees. I had a false positive last week when I should have just looked at the rx the cpu was seeing when trying to get an SPI peripheral working on a new chip.

So I may be in the market for a better analyzer soon. But all in all my $30 was a good investment, and has made it easier to setup new serial protocols.