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");

}

}