int SIGNAL; 
void setup(){
pinMode(21, INPUT); // Aux Channel (CH3 or CH4)
pinMode(3, OUTPUT); // Blinking Lights
pinMode(5, OUTPUT); // Landing Lights
pinMode(9, OUTPUT); // Constant Lights
}
void loop(){
SIGNAL=pulseIn(21,HIGH);
digitalWrite(9, LOW);
digitalWrite(3, LOW);
digitalWrite(5, LOW);
if (SIGNAL>1400)
{
digitalWrite(3, HIGH);
digitalWrite(5, LOW);
for (int i = 0; i< 1250; i++) {
if (SIGNAL>1800) digitalWrite(9, HIGH); else digitalWrite(9, LOW);
delay(1);
}
digitalWrite(5, HIGH);
delay(95);
digitalWrite(5, LOW);
delay(95);
digitalWrite(5, HIGH);
}
else
{
digitalWrite(3, LOW);
digitalWrite(5, LOW);
}
}