JuanGg Projects

Just bought a second-hand Hameg HM604. It just needed some calibration and fixing a broken rod coupler to get it up an running. Here are some photographs of the inside should anyone find them useful. I didn't get into the volts/div switches, as the metal cans they are in are welded shut. Some photos of those can be found in this  EEVBlog thread. Anyway, here are some more photos:

This is a USB Polygraph, which I designed and built as a classroom project on June 2018. The hardware side is pretty simple, an Arduino UNO collects data from some sensors and sends it via serial. On the computer, a Python program takes that data and not only graphs it, but it also allows the user to save it, manages questions and adds question and answer markers to the graphs so results can later be inspected. All results are saved in .txt files. First, some legal stuff: DISCLAIMER: I make no claim whatsoever on the validity of poligraphy for lie detection. Call this a signal acquisition device if you must. While it makes for an interesting and enjoyable build, it is intended just as an experiment and cannot distinguish between truth or else. Anyway, it is up to the user to decide. Always make use of common sense. WARNING: Using this device involves attaching metal objects to someone's hand. To avoid any possibility of shock hazard, please make sure all "probes" ...