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I have a TRRS connector for my Android phone. I want to be able to enable/disable the mic on the cable using a button.

So for this I have connected a 1.2 kOhm resistor to a button and when its 'on' it will create a bridge over the Mic and ground connector, successfully muting the mic. If I leave it 'off', the microphone inputs data normally.

The problem is, the only way the Android phone uses the external MIC input when connecting the cable for the first time is when the button is 'off'. If I connect it when the button is 'on' it will not switch to the external 'muted' mic.

Is there a way to force this behavior, connecting a 'muted' microphone over the TRRS connector?

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  • \$\begingroup\$ A resistive load on the mic line means something specific to phones. Have you tried a capacitive load instead? \$\endgroup\$
    – Ignacio Vazquez-Abrams
    Commented Jul 23, 2016 at 17:26
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    \$\begingroup\$ Can you elaborate a bit more? \$\endgroup\$
    – user886869
    Commented Jul 23, 2016 at 17:33
  • \$\begingroup\$ Are you suggesting it is a digital mic as per "microphone inputs data normally"? \$\endgroup\$
    – Andy aka
    Commented Jul 23, 2016 at 18:13
  • \$\begingroup\$ @Andyaka Its just a normal analog mic, sorry about the misunderstanding \$\endgroup\$
    – user886869
    Commented Jul 23, 2016 at 19:33

1 Answer 1

Reset to default
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Use your mute switch to substitute a fixed resistor in place of the microphone capsule. Select the resistor to give an equivalent static DC voltage on the connector so that the phone will recognize the "mic".

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