Logic probes can be anything from useful to critical depending on the project, but if you don’t have one already, why not try building one? Instructables has a guide to building a logic probe using a PCB, an assorted lot of resistors, capacitors, regulators, DIP sockets, a 9V battery clip (and 9V battery), and a hex inverter. Instead of using an LED like other simple logic probes, though, this kit uses a 7 segment LED display to show whether logic high (H) or low (L). The schematic makes putting this together only slightly more complicated than snapping Legos together. Of course, the resulting device is not as versatile as a LogicPort logic analyzer, but it is still useful.
[lekernel] sent in his USB logic analyzer. I might just have to build this one for my work bench. It’s based on an Altera Cyclone 2 FPGA and he’s provided full schematics, source and a quick and dirty Linux driver to get things going. The board is nearly all surface mount, but he points out that the entire thing was soldered with a standard iron and de-soldering wick. If you’re looking for a good starter FPGA project, this looks like a good one.
I started writing for Hack-A-Day a little over a year ago. I’ve barely taken a break, but for the next week I’m going to be taking some serious time off on a Caribbean island. Thanks for a great year guys! While I’m gone, [fbz] has kindly consented to take over the reins. I’m looking forward to another year when I get back, but right now I’ve got to finish packing my dive gear.