DroonAltHold.ino

#include <PID_v1.h>
#include <Servo.h>
#include <NewPing.h>

//Define Variables we'll be connecting to
double Setpoint, Input, Output;

//Specify the links and initial tuning parameters
PID myPID(&Input, &Output, &Setpoint,2,5,1, DIRECT);

Servo myservo;

int ECHO_PIN = 10;
int TRIGGER_PIN = 16;
int MAX_DISTANCE = 450;
int OUT = 2;

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

void setup () {
  Serial.begin(960);
  pinMode(14, OUTPUT);
  digitalWrite(14, HIGH);
  
  myservo.attach(OUT);
  
  //initialize the variables we're linked to
  Input = sonar.ping_cm();
  Setpoint = 50;

  //turn the PID on
  myPID.SetMode(AUTOMATIC);
  myPID.SetOutputLimits(1150, 2000);
}

void loop () {
  Input = sonar.ping_cm();
  myPID.Compute();
  myservo.writeMicroseconds(Output);
  
  Serial.print("Ping: ");
  Serial.print(Input);
  Serial.print("cm - out: ");
  Serial.println(Output);
}

ServoPulseInHighLow.ino

int INPIN = A3;
int LOWPIN = 8;
int OUTPIN = 9;
int LOWPIN2 = 6;
int OUTPIN2 = 7;
int TRESH = 1500;
void setup() {
  // put your setup code here, to run once:
  pinMode(INPIN, INPUT);
  pinMode(OUTPIN, OUTPUT);
  pinMode(LOWPIN, OUTPUT);

  Serial.begin(9600);
  Serial.println("Tere...?");

  digitalWrite(LOWPIN, LOW);
  digitalWrite(LOWPIN2, LOW);
}

unsigned long pulse;
boolean isHigh;

void loop() {
  // put your main code here, to run repeatedly: 
  pulse = pulseIn(INPIN, HIGH);
  Serial.print("Got pulse: ");
  Serial.println(pulse);
  isHigh = (pulse >= TRESH);
  if (pulse >= TRESH) {
    Serial.print(pulse);
    Serial.print(" is GREATER than treshold of ");
    Serial.print(TRESH);
    Serial.println(".");
  } 
  else {
    Serial.print(pulse);
    Serial.print(" is LOWER than treshold of ");
    Serial.print(TRESH);
    Serial.println(".");
  }
  digitalWrite(OUTPIN, isHigh);
  digitalWrite(OUTPIN2, isHigh);
}