Method And Tech Examples

// This example uses an ESP32 Development Board

// to connect to shiftr.io.

//

// You can check on your device after a successful

// connection here: https://www.shiftr.io/try.

//

// by Joël Gähwiler

// https://github.com/256dpi/arduino-mqtt

#define ONBOARD_LED  2

#include <WiFi.h>

#include <MQTT.h>

#include <ESP32Servo.h>

Servo myservo;  // create servo object to control a servo

// 16 servo objects can be created on the ESP32

int pos = 0;    // variable to store the servo position

// Recommended PWM GPIO pins on the ESP32 include 2,4,12-19,21-23,25-27,32-33

// Possible PWM GPIO pins on the ESP32-S2: 0(used by on-board button),1-17,18(used by on-board LED),19-21,26,33-42

int servoPin = 21;

WiFiClient net;

MQTTClient client;

unsigned long lastMillis = 0;

void connect() {

  Serial.print("checking wifi...");

  while (WiFi.status() != WL_CONNECTED) {

    Serial.print(".");

    delay(1000);

  }

  Serial.print("\nconnecting...");

  while (!client.connect("arduino", "public", "public")) {

    Serial.print(".");

    delay(1000);

  }

  Serial.println("\nconnected!");

  client.subscribe("/carsharep5js");

  // client.unsubscribe("/hello");

}

void messageReceived(String &topic, String &payload) {

  Serial.println("incoming: " + topic + " - " + payload);

  if (topic.equals("/carsharep5js") && payload.equals("on"))

  {

    digitalWrite(ONBOARD_LED, HIGH);

    myservo.write(180);

  }

  else if (topic.equals("/carsharep5js") && payload.equals("off"))

  {

    myservo.write(0);

    digitalWrite(ONBOARD_LED, LOW);

  }

  // Note: Do not use the client in the callback to publish, subscribe or

  // unsubscribe as it may cause deadlocks when other things arrive while

  // sending and receiving acknowledgments. Instead, change a global variable,

  // or push to a queue and handle it in the loop after calling `client.loop()`.

}

void setup() {

  Serial.begin(9600);

  WiFi.begin("oliver", "hesthest"); // OBSMADS

  // Note: Local domain names (e.g. "Computer.local" on OSX) are not supported

  // by Arduino. You need to set the IP address directly.

  client.begin("public.cloud.shiftr.io", net);

  client.onMessage(messageReceived);

  pinMode(ONBOARD_LED, OUTPUT);

  connect();

  // Allow allocation of all timers

  ESP32PWM::allocateTimer(0);

  ESP32PWM::allocateTimer(1);

  ESP32PWM::allocateTimer(2);

  ESP32PWM::allocateTimer(3);

  myservo.setPeriodHertz(50);    // standard 50 hz servo

  myservo.attach(servoPin, 1000, 2000); // attaches the servo on pin 18 to the servo object

  // using default min/max of 1000us and 2000us

  // different servos may require different min/max settings

  // for an accurate 0 to 180 sweep

}

void loop() {

  client.loop();

  delay(10);  // <- fixes some issues with WiFi stability

  if (!client.connected()) {

    connect();

  }

  // publish a message roughly every second.

  if (millis() - lastMillis > 1000) {

    lastMillis = millis();

    client.publish("/carshareesp32", "I am online");

  }

}