Controlling Relays and LEDs Through Get Commands

In this project, you will use the Antares Shield Workshop on the ESP8266 module. In this Antares Shield Workshop, there are temperature, humidity (DHT11), relay, LED, and push button sensors. You will publish data using MQTTX which contains commands to control LEDs and relays. Then the ESP8266 Subscribes Data to the Antares IoT Platform which contains two command options, namely if the Relay input is 1 then the relay will turn on; Relay input is 0 then the relay will turn off; LED is 1 then the LED will turn on; LED input is 0 then the LED will turn off.

Prerequisites

The materials required follow the General Prerequisites on the previous page. If you have not prepared the requirements on that page, then you can visit the following page.

pageGeneral Prerequisites ESP8266 Wi-Fi

The additional materials specific to this project are as follows.

Shield Workshop Antares
Antares ESP MQTT Library. This documentation uses the Antares ESP MQTT library version 1.0.

If you have not installed Antares ESP MQTT version 1.0, you can follow these steps.

Antares Wi-Fi MQTT

MQTTX Software

If you have not installed the MQTTX Software, you can follow the steps in the following link.

MQTTX Installation

Follow These Steps

1. Launch the Arduino IDE application

2. Opening Sample Programmem

You can open the programme code in the Arduino IDE via File > Example > Antares ESP HTTP > ESP8266-Simple-Project > RETRIEVE_DATA_RELAY_LED.

Here is the programme code of the GET_DATA_RELAY_LED example.

// Include necessary libraries
#include <AntaresESPMQTT.h> // Include the ESP8266 MQTT library

// Replace these with your own credentials
#define ACCESSKEY "YOUR-ACCESS-KEY"       // Replace with your Antares account access key
#define WIFISSID "YOUR-WIFI-SSID"         // Replace with your Wi-Fi SSID
#define PASSWORD "YOUR-WIFI-PASSWORD"     // Replace with your Wi-Fi password

#define projectName "YOUR-APPLICATION-NAME"   // Replace with the Antares application name that was created
#define deviceName "YOUR-DEVICE-NAME"     // Replace with the Antares device name that was created

#define relayPin D6 // Define the pin connected to the Relay
#define ledPin D2   // Define the pin connected to the LED

const unsigned long interval = 10000;    // 10 s interval to send message
unsigned long previousMillis = 0;  // will store last time message sent

AntaresESPMQTT antares(ACCESSKEY);

void callback(char topic[], byte payload[], unsigned int length) {
  antares.get(topic, payload, length);

  Serial.println("New Message!");
  Serial.println("Topic: " + antares.getTopic());
  Serial.println("Payload: " + antares.getPayload());

  String relayValue = antares.getString("Relay"); // Change data field to "Relay"
  String ledValue = antares.getString("LED");     // Add reading for "LED" data field
  // Control relay based on received data
  if (relayValue == "1") {
  digitalWrite(relayPin, HIGH);
  } 
  else if (relayValue == "0") {
  digitalWrite(relayPin, LOW);
  }

  // Control LED based on received data
  if (ledValue == "1") {
  digitalWrite(ledPin, HIGH);
  } 
  else if (ledValue == "0") {
  digitalWrite(ledPin, LOW);
  }

  Serial.println("Received data - Relay: " + relayValue + " | LED: " + ledValue);
  
}

void setup() {
    Serial.begin(115200); // Initialize serial communication
    antares.setDebug(true); // Enable debugging for Antares
    antares.wifiConnection(WIFISSID, PASSWORD); // Connect to WiFi
    antares.setMqttServer();
    antares.setCallback(callback);
    pinMode(relayPin, OUTPUT); // Set relayPin as an output
    pinMode(ledPin, OUTPUT); // Set ledPin as an output
}

void loop() {
 /*
    Check if we're still connected to the MQTT broker/server.
    If disconnected, the device will try to reconnect.
   */
  antares.checkMqttConnection();
}

3. Set WiFi Credential and Antares Credential in Program Code

Change the HTTP Protocol parameters in the following variables *ACCESSKEY, *WIFISSID, *PASSWORD, *projectName, and *deviceName. Adjust to the parameters in the Antares console.

#define ACCESSKEY "your-access-key" // Replace with your Antares account access key
#define WIFISSID "your-wifi-ssid" // Replace with your Wi-Fi SSID
#define PASSWORD "your-wifi-password" // Replace with your Wi-Fi password

#define projectName "your-project-name"   // Antares project name
#define deviceName "YOUR-DEVICE-NAME-"    // Antares device name

The *Access key parameter is obtained from your Antares account page.

The WIFISSID parameter is obtained from the name of the Wifi / Hotspot that is currently being used by you. for example in the image below.

The *PASSWORD parameter is obtained from the WiFi password you are currently using.

The parameters *projectName, *deviceName are obtained from the Application Name and Device Name that have been created in the Antares account.

4. Compile and Upload Program

Connect the ESP8266 WEMOS D1R2 with your computer and make sure the Communication Port is read.

On Windows operating systems, checking can be done via Device Manager. If your ESP8266 WEMOS D1R2 is read, the USB-Serial CH340 appears with the port adjusting the port availability (in this case it reads COM4).

Set up the ESP8266 WEMOS D1R2 board by clicking Tools > Board > esp8266 in the Arduino IDE, then make sure the one used is LOLIN (WEMOS) D1 R2 & mini. Select the port according to the communication port that is read (in this case COM4). The result will look like the following picture.

After all the setup is complete, upload the programme by pressing the arrow icon as shown below. Wait for the compile and upload process to finish.

The Tick icon on the Arduino IDE is just the verify process. Usually used to Compile the programme to find out whether there are errors or not.

The Arrow icon on the Arduino IDE is the verify and upload process. Usually used to Compile the programme as well as Flash the programme to the target board.

If the programme upload is successful, it will look like the following image..

After uploading the programme, you can view the serial monitor to debug the programme. The serial monitor icon is shown in the following image.

Set the serial baud rate to 115200 and select BothNL & CR. The result will look like the following image.

Make sure the serial baud rate matches the value defined in the programme code. If the serial baud rate is not the same between the programme code and the serial monitor, the ASCII characters will not be read properly.

5. Setup MQTTX Software

Open the MQTTX App, then select New Connection

In order to configure MQTTX with Antares broker, adjust the Name, Host and Port as shown below, then click Connect.

If it is connected, there is a notification as shown below

To publish to the Antares server, enter Topic and Payload in the fields in MQTTX.

Field Value

Field	Value
Topic	`/oneM2M/req/your-access-key/antares-cse/json`
Payload	`{ "m2m:rqp": { "fr": "your-access-key", "to": "/antares-cse/antares-id/nama-aplikasi-anda/nama-device-anda", "op": 1, "rqi": 123456, "pc": { "m2m:cin": { "cnf": "message", "con": "{\"your-first-data\":\"the-integer-value\",\"your-second-data\":\"the-string-data\"}" } }, "ty": 4 } }`

Topic

/oneM2M/req/your-access-key/antares-cse/json

Payload

{
      "m2m:rqp": {
        "fr": "your-access-key",
        "to": "/antares-cse/antares-id/nama-aplikasi-anda/nama-device-anda",
        "op": 1,
        "rqi": 123456,
        "pc": {
          "m2m:cin": {
            "cnf": "message",
            "con": "{\"your-first-data\":\"the-integer-value\",\"your-second-data\":\"the-string-data\"}"
          }
        },
        "ty": 4
      }
    }

Customise your-access-key, your-application-name, and your-device-name to the names registered to your Antares account. Fill in the "Field" data and "Value" data in "con" as you wish.

In the MQTTX software, enter the Topic and Payload that you want to use. Then click Publish to send the message from MQTTX to the Antares server.

6. Sending MQTTX Messages to the Antares Server

After the MQTTX software setup is complete, it's time to send the PUBLISH command. The "Relay" field is filled with the string "1" for RELAY ON or "0" for RELAY OFF. The "LED" field is filled with the string "1" for LED ON or "0" for LED OFF. The "Relay" and "LED" fields are command messages to control the Relay and LED that will be sent via HTTP protocol to the Antares server.

{
      "m2m:rqp": {
        "fr": "your-access-key",
        "to": "/antares-cse/antares-id/nama-aplikasi-anda/nama-device-anda",
        "op": 1,
        "rqi": 123456,
        "pc": {
          "m2m:cin": {
            "cnf": "message",
            "con": "{\"Relay\":\"1\",\"LED\":\"1\"}"
          }
        },
        "ty": 4
      }
    }

If you have finished filling in the "Relay" and "LED" fields, then press the PUBLISH button on the MQTTX software located to the right of the Topic filling column, as shown below.

If it has been published, the MQTTX page will have a message like the following.