I intend to buy CH340G USB Microcontroller Board Arduino UNO R3 ATmega328P Development Module

I want to use it and a MOSFET or whatever needed to act as a button for a TRRS wire I already have home made to act as a call button. I know it has to be 0ohm when activated but im not sure if this can be done and with what and how.

I was hoping to have a key on my computer activate the code from the arduino which I dont mind figuring out later but I just need to get an idea on what to use for the button and how I would activate it after wiring.

  • most (all?) MOSFETs have a diode across source to drain, so that won't work very well with an AC signal like music. You could use a reed relay. The only other non-polar switch i know if is a CDS, but those might have too high a resistance here.
    – dandavis
    Jun 4, 2020 at 20:01
  • Its not being used for music just to activate like if I took a standard momentary push button from mic to gnd on the TRRS plug. But I wanna do it from Arduino so I can control it on hotkey or mouse button. Jun 4, 2020 at 20:06
  • you could likely use an nchan fet wired source to gnd, drain to the other side of the button, whatever that's connected to.
    – dandavis
    Jun 4, 2020 at 20:08
  • 1
    Better to use an opto isolator or a small reed relay to keep everything isolated.
    – Majenko
    Jun 4, 2020 at 20:09
  • 1
    a reed relay has normally open contacts
    – jsotola
    Jun 4, 2020 at 22:53


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