# Retrieve Data displayed on OLED Display

In this project, you will use the **Antares Workshop Shield** on the **Lynx-32 Development Board** module. In this **Antares Shield Workshop**, there are temperature, humidity (DHT11), relay, LED and push button sensors. You will monitor the temperature and humidity according to the specified interval period. The results of the data sent by the sensors can be monitored through the Antares console.

## 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-esp32-wi-fi" %}
[general-prerequisites-esp32-wi-fi](https://docs.antares.id/en/code-and-library-examples/esp32-wi-fi/general-prerequisites-esp32-wi-fi)
{% endcontent-ref %}

The additional materials specific to this project are as follows.

1. Shield Workshop Antares
2. I2C-based 0.96inch 128x64 pixel SSD1036 OLED module

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/9UFPaiTpg45WCq7rHyi1/WhatsApp%20Image%202023-09-06%20at%2014.39.49.jpeg" alt="" width="345"><figcaption><p>SSD1036 0.96inch OLED Module Picture</p></figcaption></figure>

3. Antares ESP HTTP Library. This documentation uses the **Antares ESP MQTT library version 1.0.**

{% hint style="info" %}
If you have not installed **Antares ESP MQTT version 1.0**, you can follow these steps.

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

4. DHT11 Library. This documentation uses **DHT11 Sensor Library version 1.4.4.**

{% hint style="info" %}
If you have not installed the **DHT11 Sensor Library version 1.4.4.** you can follow the steps in the following link.

[dht11-sensor-library](https://docs.antares.id/en/getting-started/arduino-library-installation/dht11-sensor-library "mention")
{% endhint %}

5. SSD1306 OLED Library. This documentation uses **Adafruit SSD1306 by Adafruit version 2.5.7.**

{% hint style="info" %}
If you have not installed the **Adafruit SSD1306 by Adafruit library version 2.5.7.** you can follow the steps in the following link.

[adafruit-ssd1306](https://docs.antares.id/en/getting-started/arduino-library-installation/adafruit-ssd1306 "mention")
{% endhint %}

6. MQTTX Software

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

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

## Follow These Steps

### 1. Launch the Arduino IDE application

### 2. Opening Sample Programme

{% hint style="info" %}
You can open the programme code in the Arduino IDE via **File > Examples > Antares ESP MQTT > Lynx32-Simple-Project > RETRIEVE\_DATA\_OLED.**
{% endhint %}

Here is the **RETRIEVE\_DATA\_OLED** example programme code.

```arduino
#include <AntaresESPMQTT.h>  // Import the AntaresESPMQTT library for communication with Antares
#include <Adafruit_SSD1306.h>  // Import the Adafruit_SSD1306 library for controlling the OLED display

#define ACCESSKEY "YOUR-ACCESS-KEY"       // Antares account access key
#define WIFISSID "YOUR-WIFI-SSID"         // Wi-Fi SSID to connect to
#define PASSWORD "YOUR-WIFI-PASSWORD"     // Wi-Fi password

#define projectName "YOUR-APPLICATION-NAME"   // Name of the application created in Antares
#define deviceName "YOUR-DEVICE-NAME"     // Name of the device created in Antares

AntaresESPMQTT antares(ACCESSKEY);  // Initialize the AntaresESPMQTT object with the access key

#define SCREEN_WIDTH 128  // OLED display width
#define SCREEN_HEIGHT 64  // OLED display height
#define OLED_RESET -1  // OLED display reset pin

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);  // Initialize the display object

void callback(char topic[], byte payload[], unsigned int length) {
  // Callback function to be executed when a message is received
  antares.get(topic, payload, length);

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

  String receivedData = antares.getString("Test");
  Serial.println("Received: " + receivedData);

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Received: " + receivedData);
  display.display();
}

void setup() {
  Serial.begin(115200);  // Start serial communication at baud rate 115200
  antares.setDebug(true);  // Enable debug mode for Antares
  antares.wifiConnection(WIFISSID, PASSWORD);  // Connect to Wi-Fi using SSID and password
  antares.setMqttServer();  // Set up the Antares MQTT server
  antares.setCallback(callback);  // Set the callback function for MQTT messages

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {  // Initialize the OLED display
    Serial.println(F("SSD1306 allocation failed"));  // Display a message if OLED initialization fails
    for (;;) ;  // Halt the program
  }

  display.clearDisplay();  // Clear the OLED display
  display.setTextSize(1);  // Set text size
  display.setTextColor(SSD1306_WHITE);  // Set text color
  display.setCursor(0, 0);  // Set text cursor position
  display.println("Waiting for data...");  // Display initial message
  display.display();  // Show the message on the display
}

void loop() {
  antares.checkMqttConnection();  // Check MQTT connection to Antares
}
```

### 3. Set WiFi Credential and Antares Credential in Program Code&#x20;

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

```arduino
#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
```

{% 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%2FAkCn9n3I0LoqUyub4tqd%2Fimage.png?alt=media&#x26;token=65783493-c9b6-4b47-bdfa-78d10fc212a1" alt=""><figcaption><p>Access Key Location on Antares Account Page</p></figcaption></figure>

{% hint style="info" %}
The **WIFISSID** parameter is obtained from the **Wi-Fi/Hotspot** name that will be used by the **Lynx-32 Development Board**. An example is shown below.
{% endhint %}

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/9wDzLE3y2CRRd1FDFO8V/2.png" alt=""><figcaption><p>WIFISSID</p></figcaption></figure>

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

{% hint style="info" %}
The parameters **\*projectName** and **\*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%2FuSSXDflXQTeARUJ2EwFW%2Fimage.png?alt=media&#x26;token=16d22b22-649a-4976-b93d-e3f69d54595e" 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%2FDOtbhIyX5626x4nroXMl%2Fimage.png?alt=media&#x26;token=0d4bcbcb-e211-4724-af79-31b3c362d1e4" alt=""><figcaption><p>Device Name Display</p></figcaption></figure>

### 4. Compile and Upload Program

Connect the **Lynx-32** with your computer and make sure the **Communication Port** is read.

{% hint style="info" %}
On Windows operating systems the check can be done via **Device Manager**. If your **Lynx-32** is read then 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/0kmgt2jom0ocT5CHNA54/4.PNG" alt=""><figcaption><p>Device Manager Display</p></figcaption></figure>

Set up the **ESP32** board by clicking **Tools > Board > esp32** in the Arduino IDE, then make sure the **ESP32 Dev Module** is used. Select the port according to the communication port that is read (in this case COM4). The result will look like the following image.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/gIqdJvSCjvt9BPxFUDUf/5.png" alt="" width="464"><figcaption><p>Display of Board Specifications and Ports Used</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/3B85fLD3HZKop3KFvIam/6.PNG" alt=""><figcaption><p>Compile Icon for Tick and Upload Icon for Arrow</p></figcaption></figure>

{% hint style="info" %}
**The Tick icon** on the Arduino IDE is just the verify process. Usually used to C**ompile** 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.
{% endhint %}

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/KeLqQwO6jvVKsDIjMgUi/7.PNG" 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/nA3mUw7Fcxq0DO36Ilee/8.png" alt=""><figcaption><p>Serial Monitor Icon</p></figcaption></figure>

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/8x0jzHhgXBWxxTvzdA81/4_sm.PNG" alt=""><figcaption><p>Serial Monitor Display</p></figcaption></figure>

{% 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 %}

### 5. MQTTX Software Setup

**Open the MQTTX App, then select New Connection**

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/1Qf76slCEoCoPHY8EaOn/New%20Connection%20MQTTX.jpg" alt=""><figcaption><p>Creating a New Connection</p></figcaption></figure>

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/dNBW0rKB5prlnMoAuJBU/Configuration%20MQTTX.jpg" alt=""><figcaption><p>Antares MQTT Broker Configuration</p></figcaption></figure>

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

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/6skt10X3v8JfmU8RHIcd/Connected%20MQTTX.jpg" alt=""><figcaption><p>Antares Broker MQTTX Connected</p></figcaption></figure>

Enter **Topic** and **Payload** in the fields in MQTTX.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/CXpcEzhL2lqavulFfoUA/Topic%20dan%20Payload%20MQTTX.jpg" alt=""><figcaption><p>Topic and Payload pages in MQTTX</p></figcaption></figure>

<table><thead><tr><th width="111">Field</th><th>Value</th></tr></thead><tbody><tr><td><strong>Topic</strong></td><td><mark style="color:red;"><code>/oneM2M/req/your-access-key/antares-cse/json</code></mark></td></tr><tr><td><strong>Payload</strong></td><td><pre class="language-json"><code class="lang-json">{
      "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
      }
    }
</code></pre></td></tr></tbody></table>

{% hint style="info" %}
Customise <mark style="color:red;">your-access-key</mark>, <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. Fill in the "Field" data and "Value" data in "con" as you wish.
{% endhint %}

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.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/QBATHqNKro8I254CpH7M/Publish%20to%20Antares%20MQTTX.jpg" alt=""><figcaption><p>Publish to send the message to the Antares server</p></figcaption></figure>

### **6.** Sending MQTTX Messages to Antares Server

After the MQTTX software setup is complete, it's time to send the PUBLISH command. The "Test" field is filled with the string "Hello Antares" as the message that will be sent via the MQTT protocol to the Antares server.

```json
{
      "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": "{\"Test\":\"Hallo Antares\"}"
          }
        },
        "ty": 4
      }
    }
```

If you have finished filling in the "Test" field, then press the **Publish** button on the MQTTX software, as shown below.

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/u68HsJOPnxwcp1Jmh15P/Payload%20Hello%20Antares%20MQTTX.jpg" alt=""><figcaption><p>Image of MQTTX Payload content</p></figcaption></figure>

Publish to send the message to the Antares server

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/xK7Uuwy7SqIO7rAOXZzQ/Published%20MQTTX.jpg" alt=""><figcaption><p>Notification Message Published</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%2FVkD2oNGxros20okpKYFY%2Fimage.png?alt=media&#x26;token=c47dc805-e2ad-474e-8674-c84eb956528a" alt=""><figcaption></figcaption></figure>

<figure><img src="https://3873791589-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F7cujmJ5QHdJaAjH815aZ%2Fuploads%2FYAvB0hSHZKBK3vneqDC4%2Fimage.png?alt=media&#x26;token=178ac849-34c3-4308-991f-01b22d7a6f54" alt=""><figcaption><p>Image of the Antares Console Page When Data is Successfully Received.</p></figcaption></figure>

{% hint style="info" %}
The data received by LYNX-32 with the MQTT protocol is in the form of Test variables.
{% endhint %}

### 8. View Retrieve Message&#x20;

Retrieve data from the **Antares IoT Platform** and display it on the OLED display after connecting to Wi-Fi as shown in the figure below:

<figure><img src="https://content.gitbook.com/content/7cujmJ5QHdJaAjH815aZ/blobs/bah0EgATn5qYEslTM6zf/IMG_20230830_104424.jpg" alt=""><figcaption><p>OLED Display</p></figcaption></figure>