Hi Daisy,

I agree with Mahmood, I prefer looking at signals with a scope or logic analyzer so I can actually see what is going on. Yet I've debugged many a circuit with a logic probe...and sometimes with just an LED.

If you're going to be doing debug with a logic probe, buy a decent one with switchable TTL/CMOS logic levels, and pulse recognition. The latter will let you know that a signal isn't DC, that the signal is going up and down...but exactly how the signal is wiggling you won't know without a scope.

A logic probe is an inexpensive tool for the toolbox.

Dennis