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.
[Travis Goodspeed] has updated his syringe based logic probe that we covered earlier. Instead of soldering to the outside, he’s using silver wire shoved into the core of the needle. A nice side benefit is the safety cap now fits. Inside the syringe are two LEDs that indicate current direction. The sharp needle makes it a lot easier to hit small traces.
I’m sick today, but finally getting some entries up. [Albert] designed this board which can be either a low voltage PIC programmer or, if you lack a programmer to get the initial flash data on the PIC, the through hole components make a logic probe. He rounded out the board with a silk screened logo and a prototyping area. He was also kind enough to provide an eagle library with the Hack-A-Day logo.
Our second featured entry of the day: [Pablo] put together a simple Hack-A-Day 2.4ghz antenna. He built and tested it – It functions nicely as a directional 2db antenna. His proposed use: limit your neighbors access to your AP by aiming the unetched backside at them.