Retrieve Last Data from Antares Server with MQTT Protocol
In this project, you will be directed to retrieve data from Antares IoT Platform to ESP8266 using WiFi connectivity with MQTT protocol.
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.
General Prerequisites ESP8266 Wi-FiThe additional materials specific to this project are as follows.
Antares ESP MQTT Library. This documentation uses the Antares ESP MQTT library version 1.0.
Follow These Steps
1. Launch the Arduino IDE application
2. Opening Sample Programme
Below is the GetLatestData sample programme code.
/*
This code will fetch the latest data from your antares project device.
Your Antares project device must have a structure like this:
(Note that nesting the JSON object can only be done up to 2 levels using this library)
{
"temperature": some-integer,
"humidity": some-integer,
"wind_speed": some-float,
"rain_level": some-float,
"location" : {
"latitude": "static-string",
"longitude": "static-string"
}
}
For more information please visit https://antares.id/id/docs.html
*/
#include <AntaresESPHTTP.h> // Include the AntaresESP32HTTP 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-project-name" // Antares project name
#define deviceName "your-project-name" // Name of the device
AntaresESPHTTP antares(ACCESSKEY); // Initialize AntaresESP32HTTP with the access key
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
}
void loop() {
// Get the latest data from your Antares device
antares.get(projectName, deviceName);
// Check if we're actually getting data
if (antares.getSuccess()) {
int temp = antares.getInt("temperature");
int hum = antares.getInt("humidity");
float windsp = antares.getFloat("wind_speed");
float rainlv = antares.getFloat("rain_level");
String lat = antares.getString("location", "latitude");
String lon = antares.getString("location", "longitude");
Serial.println("Temperature: " + String(temp));
Serial.println("Humidity: " + String(hum));
Serial.println("Wind speed: " + String(windsp));
Serial.println("Rain level: " + String(rainlv));
Serial.println("Latitude: " + lat);
Serial.println("Longitude: " + lon);
}
delay(5000);
}
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-project-name" // Name of the device




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

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.

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. Check Data in Serial Monitor
After uploading the programme successfully, then open the Serial Monitor page and see if the data has been successfully retrieved.



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