View source for Arduino Nano: PTT VOX via Analog Out Mic

 /*
   Rig PTT VOX
   Detect A0 dari Audio
   Output D5 ke Switch
 
   modified 2021 Dec 3
   by Onno W. Purbo
  */
 
 int State=LOW;
 int inPin=A0;
 int outPin=5; 
 
 void setup() {
   pinMode(outPin, OUTPUT);
 }
 
 void loop() {
   State=analogRead(inPin);
   if( State>30) digitalWrite(outPin, HIGH);
   else digitalWrite(outPin, LOW);
   delay(100);
 }