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 monitor the temperature and humidity according to the specified interval period. The results of the data sent by the sensor can be monitored through the Antares console and displayed on the OLED.
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.
The additional materials specific to this project are as follows.
You can open the programme code in the Arduino IDE via File > Example > Antares ESP HTTP > ESP8266-Simple-Project > SEND_DATA_DHT11_OLED.
Below is the programme code of the SEND_DATA_DHT11_OLED example.
// Library initialization#include<AntaresESPMQTT.h>// Library initiation for Antares ESP8266 MQTT#include"DHT.h"// Load DHT sensor library for reading temperature and humidity#include<Adafruit_SSD1306.h>// Load OLED display library#defineDHTPIN D1 // Define DHTPIN variable, pointing to pin D1#defineDHTTYPE DHT11 // Set DHT type to DHT11#defineSCREEN_WIDTH128 // Define OLED screen width#defineSCREEN_HEIGHT64 // Define OLED screen height#defineOLED_RESET-1 // Define OLED reset pin, set to -1 as it's not used#defineSCREEN_ADDRESS0x3C // Define OLED I2C address#defineACCESSKEY"YOUR-ACCESS-KEY" // Replace with your Antares account access key#defineWIFISSID"YOUR-WIFI-SSID" // Replace with your Wi-Fi SSID#definePASSWORD"YOUR-WIFI-PASSWORD" // Replace with your Wi-Fi password#defineprojectName"YOUR-APPLICATION-NAME" // Replace with the Antares application name that was created#definedeviceName"YOUR-DEVICE-NAME" // Replace with the Antares device name that was createdconstunsignedlong interval =10000; // 10 s interval to send messageunsignedlong previousMillis =0; // will store last time message sentAntaresESPMQTT antares(ACCESSKEY); // Create an antares object for connecting to Antares
DHTdht(DHTPIN,DHTTYPE); // Create a dht object for the DHT sensorAdafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET); // Create a display object for the OLED screen
voidsetup() {Serial.begin(115200); // Initialize serial communication with baudrate 115200 antares.setDebug(true); // Turn on debug mode. Set to "false" if you don't want messages to appear in the serial monitor
antares.wifiConnection(WIFISSID, PASSWORD); // Attempt to connect to Wi-Fi with the specified SSID and passwordantares.setMqttServer();dht.begin(); // Initialize the DHT sensor objectif (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {Serial.println(F("SSD1306 allocation failed")); // Check if the OLED is successfully initializedfor (;;) ; }display.clearDisplay(); // Clear the OLED displaydisplay.setTextColor(SSD1306_WHITE); // Set text color to whitedisplay.setTextSize(1); // Set text size to 1display.setCursor(0,0); // Set cursor position to (0, 0)display.println(F("Temperature & Humidity")); // Display "Temperature & Humidity" text on the OLEDdisplay.display(); // Show the text on the OLEDdelay(2000); // Delay for 2 seconds}voidloop() {antares.checkMqttConnection(); // Check interval overflowif (millis() - previousMillis > interval) { previousMillis =millis();float hum =dht.readHumidity(); // Read humidity value from the DHT sensorfloat temp =dht.readTemperature(); // Read temperature value from the DHT sensorif (isnan(hum) ||isnan(temp)) { // Check if the sensor reading is invalidSerial.println("Failed to read DHT sensor!"); // If the reading is invalid, print an error messagereturn; // Exit the loop function and wait for the next cycle }display.clearDisplay(); // Clear the OLED displaydisplay.setTextSize(1); // Set text size to 1display.setCursor(0,0); // Set cursor position to (0, 0)display.print(F("Temperature: ")); // Display "Temperature: " text on the OLEDdisplay.print(temp); // Display temperature value on the OLEDdisplay.println(F(" C")); // Display " C" (for Celsius) on the OLEDdisplay.print(F("Humidity: ")); // Display "Humidity: " text on the OLEDdisplay.print(hum); // Display humidity value on the OLEDdisplay.println(F(" %")); // Display " %" (for percentage) on the OLEDdisplay.display(); // Show the text on the OLED Serial.println("Temperature: " + (String)temp + " *C"); // Print temperature value to the serial monitor with "*C" format
Serial.println("Humidity: " + (String)hum + " %"); // Print humidity value to the serial monitor with "%" format
// Add variable data to the storage buffer in Antaresantares.add("temperature", temp);antares.add("humidity", hum); // Send data from the storage buffer to Antaresantares.publish(projectName, deviceName); }}
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 and *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. Check Data in Antares
After uploading the programme successfully, then open the device antares page and see if the data has been successfully sent.
Data sent from ESP8266 with HTTP protocol in the form of temperature and humidity variables.
6. Output program
DHT 11 data sent and displayed on the OLED display after connecting to Wi-Fi is shown in the figure below:
