{"version":1,"type":"rich","provider_name":"Libsyn","provider_url":"https:\/\/www.libsyn.com","height":90,"width":600,"title":"episode 19:  hand-held scopes, disassembling scales, and a digital probe","description":"(First of all, apologies for the many &quot;uhhh&quot;s and &quot;ummm&quot;s you can hear - no idea what was going on there. Edited out a lot, and next time it should be better.) Topics this time are my effort so far for the RetroChallenge 2018\/04 (25% in), a short and biased discussion of some available handheld oscilloscopes, disassembling consumer-scales to see what was going on inside, hacking together a small digital probe to distinguish high\/low\/floating pins, and blowing a fuse while poking at electronics.&amp;nbsp; --- Links\/show-notes, in that order:   my effort this week for the&amp;nbsp;RetroChallenge 2018\/04 (April) some portable scopes:  the ones I used:&amp;nbsp;  Velleman HPS140i&amp;nbsp;(1-channel) Velleman WFS210 (WiFi, 2-channel) Seeedstudio DSO Nano v1&amp;nbsp;(1-channel)   nice but starting from approx EUR 400:  Owon HDS series Micsig tBook series Siglent SHS series   PC-based:  Owon VDS series LabNation SmartScope&amp;nbsp;(software any good..?)     Awesome Space&amp;nbsp;retro-place (Utrecht, NL) Makersbase&amp;nbsp;fablab (Breda, NL) Hackalot&amp;nbsp;hackspace (Eindhoven, NL)  W.r.t the blown fuse: I made the rookie mistake of connecting probe-ground to something main-referenced (but not earth)... #makeagoodfirstimpression --- Some pics of scales-disassembly:  (load-sensor mounted in one of the scales' 4 feet)  (strain-gauge element (?) embedded in metal spring-thing) Note that when the metal thing is flexed, both &quot;halves&quot; of the element would decrease in resistance - a few hundred Ohms when flexing them by hand. That's why I don't understand why there were 3 wires bonded to this thing. Why not use 2? (From what I read and discussed with a friend, one &quot;half&quot; would ideally have to have a constant or at least less-decreasing-when-flexed resistance, to be used in a Wheatstone bridge.) --- Schematic and pics of the digital probe:   &amp;nbsp; (probe in a blob of hot-glue) &amp;nbsp; ","author_name":"CBA Podcast","author_url":"http:\/\/podcast.cba.si","html":"<iframe title=\"Libsyn Player\" style=\"border: none\" src=\"\/\/html5-player.libsyn.com\/embed\/episode\/id\/6456349\/height\/90\/theme\/custom\/thumbnail\/yes\/direction\/forward\/render-playlist\/no\/custom-color\/88AA3C\/\" height=\"90\" width=\"600\" scrolling=\"no\"  allowfullscreen webkitallowfullscreen mozallowfullscreen oallowfullscreen msallowfullscreen><\/iframe>","thumbnail_url":"https:\/\/assets.libsyn.com\/secure\/item\/6456349"}