# 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 **Post Data** using **POSTMAN** software that contains commands to control the LEDs and relays. Then the **ESP8266** performs **Get Data** from 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.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/wzmmSK55WfJeg9nTMXS0/BoardESP8266+SHIELD+OLED.jpeg" alt="" width="563"><figcaption><p>Picture of ESP8266 attached to Antares Shield</p></figcaption></figure>

## 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.

{% content-ref url="../../general-prerequisites-esp8266-wi-fi" %}
[general-prerequisites-esp8266-wi-fi](https://docs.antares.id/en/code-and-library-examples/esp8266-wi-fi/general-prerequisites-esp8266-wi-fi)
{% endcontent-ref %}

The additional materials specific to this project are as follows.

1. Shield Workshop Antares
2. Antares ESP HTTP Library. This documentation uses the **Antares ESP HTTP library version 1.4.0.**

{% hint style="info" %}
If you have not installed **Antares ESP HTTP 1.4.0**, please follow these steps.

[antares-wi-fi-http](https://docs.antares.id/en/getting-started/arduino-library-installation/antares-wi-fi-http "mention")
{% endhint %}

3. POSTMAN Software&#x20;

{% hint style="info" %}
If you have not installed **POSTMAN Software**, you can follow the steps in the following link.

[postman-installation](https://docs.antares.id/en/getting-started/software-installation/postman-installation "mention")
{% endhint %}

## Follow These Steps

### **1.** Launch the Arduino IDE application

### **2. Membuka Contoh Program**&#x20;

{% hint style="info" %}
You can open the programme code in the Arduino IDE via **File > Example > Antares ESP HTTP > ESP8266-Simple-Project > GET\_DATA\_RELAY\_LED.**&#x20;
{% endhint %}

Here is the programme code of the  **GET\_DATA\_RELAY\_LED** example.

```cpp
#include <AntaresESPHTTP.h>  // Include the AntaresESP8266HTTP library

#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"  // Antares project name
#define deviceName "YOUR-DEVICE-NAME"        // Name of the device receiving data from POSTMAN

AntaresESPHTTP antares(ACCESSKEY);  // Initialize AntaresESP8266HTTP with the access key

#define relayPin D6  // Digital pin for controlling the relay
#define ledPin D2    // Digital pin for controlling the LED

const unsigned long interval = 10000;  // 10 seconds interval to send message
unsigned long previousMillis = 0;      // Will store the last time a message was sent

void setup() {
  Serial.begin(115200);                        // Initialize serial communication
  antares.setDebug(true);                      // Enable Antares library debug mode
  antares.wifiConnection(WIFISSID, PASSWORD);  // Connect to WiFi using provided SSID and password

  pinMode(relayPin, OUTPUT);  // Set relay pin as output
  pinMode(ledPin, OUTPUT);    // Set LED pin as output
}

void loop() {

  if (millis() - previousMillis > interval) {  // Check if it's time to send a message
    previousMillis = millis();                 // Update the last sent time

    antares.get(projectName, deviceName);  // Get data from Antares

    if (antares.getSuccess()) {                       // Check if data retrieval was successful
      String dataValue = antares.getString("Relay");  // Get the value of "Relay" data field
      String ledValue = antares.getString("LED");     // Get the value of "LED" data field

      // Control relay based on received data
      if (dataValue == "1") {
        digitalWrite(relayPin, HIGH);  // Turn on the relay
      } else if (dataValue == "0") {
        digitalWrite(relayPin, LOW);  // Turn off the relay
      }

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

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

### **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.

```cpp
#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"     // Antares project name
#define deviceName "YOUR-DEVICE-NAME-"    // Name of the device receiving data from POSTMAN
```

{% hint style="info" %}
The **\*Access key** parameter is obtained from your Antares account page.
{% endhint %}

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2FZ5yM1lwupP5bKn5xPAYM%2Fimage.png?alt=media&#x26;token=27629183-068c-4034-ad47-65d054cae580" alt=""><figcaption><p>Access Key Location on Antares Account Page</p></figcaption></figure>

{% hint style="info" %}
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.
{% endhint %}

<div align="center" data-full-width="true"><figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/bAEcmOkmcUDBUIBx6ddw/WIFI%20SSID.jpeg" alt="" width="375"><figcaption><p>The WiFi SSID being used.</p></figcaption></figure></div>

{% hint style="info" %}
The **\*PASSWORD** parameter is obtained from the **WiFi password** you are currently using.
{% endhint %}

{% hint style="info" %}
The parameters **\*projectName, \*deviceName** are obtained from the **Application Name** and **Device Name** that have been created in the Antares account.
{% endhint %}

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2FpCDlXW91wNbFOUSnRu8n%2Fimage.png?alt=media&#x26;token=17b1b6fa-b16f-42fd-858a-9ec78123a3b0" alt=""><figcaption><p>Application Name Display</p></figcaption></figure>

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2Fk51Qg3KUer8R2BYju3xQ%2Fimage.png?alt=media&#x26;token=8532fd4b-ae34-44a6-9438-88a46f1f7b4e" alt=""><figcaption><p>Device Name Display</p></figcaption></figure>

### **4. Compile and Upload Program**

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

{% hint style="info" %}
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**).
{% endhint %}

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/26abmVvKzSWogDb4qo1C/Device%20Manager%20Windows.jpeg" alt=""><figcaption><p>Device Manager image on Windows.</p></figcaption></figure>

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.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/oRzTLzJkUYH9jFFcxoC0/Menu%20Tools%20Arduino%20IDE.jpeg" alt="" width="563"><figcaption><p>Image of Tools Menu on Arduino IDE</p></figcaption></figure>

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.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/56l3rHVZc4jBd4pPBZEw/Icon%20Verify%20dan%20Upload%20pada%20Arduino%20IDE.jpeg" alt=""><figcaption><p>Image of the Verify and Upload icons in the Arduino IDE.</p></figcaption></figure>

{% hint style="info" %}
**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.&#x20;

**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.
{% endhint %}

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/hqKxRuMW4Yxm2Zj3fKPQ/Halaman%20Arduino%20IDE%20Setelah%20Upload%20Berhasil.jpeg" alt=""><figcaption><p>Arduino IDE page image after successful upload.</p></figcaption></figure>

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/B4k1aFEeYrjwrDkAn4NI/Icon%20Serial%20Monitor%20pada%20Arduino%20IDE.jpeg" alt=""><figcaption><p>Image of the Serial Monitor Icon in the Arduino IDE.</p></figcaption></figure>

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

{% hint style="danger" %}
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.
{% endhint %}

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/OVP9UHYol9XRizuMJkgc/Serial%20Monitor%20GET_RELAYLED_HTTP.jpeg" alt=""><figcaption><p>Serial Monitor Image</p></figcaption></figure>

### **5. Setup POSTMAN Software**

In this step you need POSTMAN software, you can input the **end-point, request header** and **request** body first by following the following format.

**End Point**&#x20;

<table data-header-hidden><thead><tr><th width="134.5"></th><th></th></tr></thead><tbody><tr><td><strong>Method</strong></td><td>POST</td></tr><tr><td><strong>URL</strong></td><td>https://platform.antares.id:8443/~/antares-cse/antares-id/<mark style="color:red;">your-application-name/your-device-name</mark></td></tr></tbody></table>

{% hint style="info" %}
Customise <mark style="color:red;">your-application-name</mark> and <mark style="color:red;">your-device-name</mark> to the names registered to your Antares account.
{% endhint %}

**Request Header**

<table data-header-hidden><thead><tr><th width="134.5"></th><th></th></tr></thead><tbody><tr><td><strong>Key</strong></td><td><strong>Value</strong></td></tr><tr><td>X-M2M-Origin</td><td><mark style="color:red;">your-access-key</mark></td></tr><tr><td>Content-Type</td><td>application/json;ty=4</td></tr><tr><td>Accept</td><td>application/json</td></tr></tbody></table>

{% hint style="info" %}
Customise <mark style="color:red;">your-access-key</mark> with your Antares account access key.
{% endhint %}

The result will be as shown below.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/7p87ee4RDHN5micRaC2h/POSTMAN%201.png" alt=""><figcaption><p>Image of end-point and header settings in POSTMAN software.</p></figcaption></figure>

Next, you need to input the request body by following the following format.

**Request Body**

```json
{
  "m2m:cin": {
    "con": "{\"key1\":\"integer-value\", \"key2\":\"string-value\", \"keyN\":\"valueN\"}"
  }
}
```

In the POSTMAN software, select the **Body** tab then select **raw** and enter the payload according to the request body you want to use as shown below.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/gCm9rHiAXIzQI32ZKM3I/POSTMAN2.png" alt=""><figcaption><p>Image of the contents of the payload request body in POSTMAN software.</p></figcaption></figure>

{% hint style="info" %}
Customise the contents of the "con" field according to the "key" and "value" you want to send.
{% endhint %}

### **6.** Sending POSTMAN Messages to the Antares Server

After the POSTMAN software setup is complete, it's time to send the POST 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.

```json
{
  "m2m:cin": {
    "con": "{\"Relay\":\"0\", \"LED\":\"0\"}" 
  }
}
```

{% hint style="info" %}
Customise the contents of the "Relay" and "LED" fields according to the downlink command you want to send. Give a value of "1" or "0" to switch on or off.
{% endhint %}

If you have finished filling in the "Relay" and "LED" fields, then press the Send button on the POSTMAN software. Looks like the following picture.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/o3pVsnC0IB2yyOIBWDEs/Gambar%20isi%20pesan%20pada%20software%20POSTMAN..jpeg" alt=""><figcaption><p>Image of the message content in POSTMAN software.</p></figcaption></figure>

If the HTTP request through POSTMAN software is successful, the POSTMAN software response section will appear as shown below

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/aumZexqmnsTJHQuUtXRa/Gambar%20response%20hit%20API%20pada%20software%20POSTMAN..jpeg" alt=""><figcaption><p>Image of API hit response in POSTMAN software.</p></figcaption></figure>

### **7.** Check Data in Antares

After uploading the programme successfully, then open the device antares page and see if the data has been successfully sent.

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2FvTyNO1av9abARRYXgbB4%2Fimage.png?alt=media&#x26;token=9671f702-e190-4358-942a-42356601969d" alt=""><figcaption></figcaption></figure>

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2FpBeyzeaak38f21zckD6Q%2Fimage.png?alt=media&#x26;token=602c3603-ddc4-4018-be4e-564ae268ec12" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
Data received by **ESP8266** with HTTP protocol in the form of Relay and LED variables.
{% endhint %}

### 8. Output program&#x20;

Get data from the **Antares IoT Platform** and drive the relay and switch on the LED.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/9UBDbn9nNMFrh6i26Pm4/Relay%20ON%20LED%20ON.jpeg" alt=""><figcaption><p>Relay and LED ON Result</p></figcaption></figure>