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1. Embed this notice
   Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:21:15 JST Ryan Castellucci (they/them) :nonbinary_flag:

   I made a thing! Can anyone guess what it is/does?

   • Embed this notice
     ../kajer/. (kajer@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:22:17 JST ../kajer/.

     in reply to

     @ryanc im guessing it resonates at a very specific frequency

   • Embed this notice
     mx alex tax1a - 2020 (6) (atax1a@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:23:00 JST mx alex tax1a - 2020 (6)

     in reply to

     @ryanc dead bug QRP power amplifier

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:31:21 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • ../kajer/.

     @kajer It does not resonate.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:33:06 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • mx alex tax1a - 2020 (6)

     @atax1a It is not an amplifier.

   • Embed this notice
     mx alex tax1a - 2020 (6) (atax1a@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:33:56 JST mx alex tax1a - 2020 (6)

     in reply to

     @ryanc oscillator, then?

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:36:32 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • amy :neocat_cofe:

     @amy I mean... technically yes, but the same could be said for many things in my home.

   • Embed this notice
     amy :neocat_cofe: (amy@sk.girlthi.ng)'s status on Thursday, 18-Jun-2026 04:36:42 JST amy :neocat_cofe:

     in reply to

     @ryanc@infosec.exchange crimes against electricity

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:37:47 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • mx alex tax1a - 2020 (6)

     @atax1a It is not a level converter.

   • Embed this notice
     mx alex tax1a - 2020 (6) (atax1a@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:37:48 JST mx alex tax1a - 2020 (6)

     in reply to

     @ryanc (reads thread) ah, not oscillating either. high-powered level converter? :D

   • Embed this notice
     ../kajer/. (kajer@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:38:37 JST ../kajer/.

     in reply to

     @ryanc my next guess is some sort of "mouse jiggler" for touch sensitive things

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:42:46 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • kwayk42

     @kwayk42 Fortunately not yet (and I have put it into service).

   • Embed this notice
     kwayk42 (kwayk42@sechtor.social)'s status on Thursday, 18-Jun-2026 04:42:47 JST kwayk42

     in reply to

     @ryanc ✋✋✋ Does it explode?

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:44:06 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • ../kajer/.

     @kajer Nope.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:44:48 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • John Deters

     @targetdrone The DIP chip is not an optoisolator.

   • Embed this notice
     John Deters (targetdrone@mastodon.social)'s status on Thursday, 18-Jun-2026 04:44:49 JST John Deters

     in reply to

     @ryanc An opto-isolated power switch?

   • Embed this notice
     John Deters (targetdrone@mastodon.social)'s status on Thursday, 18-Jun-2026 04:58:00 JST John Deters

     in reply to

     @ryanc So it's a blinking light flasher.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:58:00 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • John Deters

     @targetdrone No, and having consulted a dictionary, it definitely doesn't oscillate.

   • Embed this notice
     John Deters (targetdrone@mastodon.social)'s status on Thursday, 18-Jun-2026 04:58:01 JST John Deters

     in reply to

     @ryanc A Very Specific Denial. A power switch operated by a deadbug 8 pin package that is neither an op amp nor a 555 timer (you said it didn't oscillate, but a resistor-capacitor controlling a 555 makes it an oscillator, so I have to believe it's not a 555.) Aha! It's a debounce circuit to flip the switch. With a 555 that is not astable.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 04:58:01 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • John Deters

     @targetdrone I said it doesn't resonate.

   • Embed this notice
     John Deters (targetdrone@mastodon.social)'s status on Thursday, 18-Jun-2026 05:08:40 JST John Deters

     in reply to

     @ryanc One last guess and I'll give up: a capacitive touch switch?

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 05:08:40 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • John Deters

     @targetdrone No, not a touch switch.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 05:14:45 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • Nuclear Oatmeal :paranoid:

     @NuclearOatmeal Not a sensor.

   • Embed this notice
     Nuclear Oatmeal :paranoid: (nuclearoatmeal@beige.party)'s status on Thursday, 18-Jun-2026 05:14:46 JST Nuclear Oatmeal :paranoid:

     in reply to

     @ryanc

     It is... A machine that goes ping.

     I dunno. I half lean toward it being a sensor of some sort, but of what, I do not know.

   • Embed this notice
     ../kajer/. (kajer@infosec.exchange)'s status on Thursday, 18-Jun-2026 06:28:34 JST ../kajer/.

     in reply to

     @ryanc my final guess: a tool used for nerd-sniping

   • Embed this notice
     Donn Castaneda (donn_castaneda@infosec.exchange)'s status on Thursday, 18-Jun-2026 06:36:14 JST Donn Castaneda

     in reply to

     @ryanc does it create something like a candle flicker? Rather than cleanly oscillating between distinct states, maybe it is deliberately unstable?

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 07:43:41 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • Donn Castaneda

     @donn_castaneda Nothing like that, no.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 07:54:35 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • Hawkuletz

     @hawkuletz You're getting close. The big resistor goes to the base of the transistor, the emitter and collector are wired to ground and trigger respectively. Discharge and control voltage are clipped off. Threshold is wired to ground. The resistors from VCC are going to trigger and reset. Output is wired to the mosfet's gate. Mosfet's source is wired to VCC.

     This is mostly visible in the photos, except for the VCC resistors and the threshold to ground connection.

   • Embed this notice
     Hawkuletz (hawkuletz@mastodon.sdf.org)'s status on Thursday, 18-Jun-2026 07:54:36 JST Hawkuletz

     in reply to

     @ryanc
     Not a sensor, not an oscillator, it doesn't resonate but it uses a 555.
     A trigger of some sort?
     That resistor probably /somhow goes to the trigger input of the 555?
     Overly complicated debouncer and level shifter?
     Soft start for some DC thingy?

   • Embed this notice
     muddle 🥣 (muddle@infosec.exchange)'s status on Thursday, 18-Jun-2026 11:30:28 JST muddle 🥣

     in reply to

     @ryanc Some sort of audio fx processor, possibly like a Theremin or capacitative equivalent?

     I thought it was most likely a 555 but noticed it was short some pins. You mentioned cutting at least two off. Without looking at the data sheet, I'm not sure what happens when those are left floating. Could be that it becomes sensitive to some kind of external interference? That was my thinking, anyway.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 14:40:28 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • muddle 🥣

     @muddle It is a 555, but not any of those things.

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Thursday, 18-Jun-2026 16:54:28 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     It's a soft power off for a raspberry pi, using the 555 as an RS flip flop. Capacitor holds the trigger low on power up to ensure the power to the Pi is off, a button connected between ground and reset boots the Pi, an GPIO on the Pi connected to the 4.7kΩ resistor drives the transistor to trip the trigger shutting off power.

   • Embed this notice
     Donn Castaneda (donn_castaneda@infosec.exchange)'s status on Sunday, 21-Jun-2026 10:42:43 JST Donn Castaneda

     in reply to

     @ryanc sorry if I'm slow.

     So the pi doesn't boot on power on, right? Then for shut down, it sounds like you have allowed a soft shutdown to latch the power off until the button gets pressed again.

     Why though? Vampire loads?

   • Embed this notice
     Ryan Castellucci (they/them) :nonbinary_flag: (ryanc@infosec.exchange)'s status on Monday, 22-Jun-2026 08:00:46 JST Ryan Castellucci (they/them) :nonbinary_flag:

     in reply to

     • Donn Castaneda

     @donn_castaneda I have a screw terminal breakout board attached to the Pi, and wish to be able to power it off easily without unplugging it

   • Embed this notice
     Donn Castaneda (donn_castaneda@infosec.exchange)'s status on Thursday, 25-Jun-2026 00:05:26 JST Donn Castaneda

     in reply to

     @ryanc ahh, neat! A clever way to create a latching button from jellybean components!